added data_type_traits for enums

# Conflicts:
#	demo/main.cpp

.gitignore

@@ -1,2 +1,4 @@
 .idea
 cmake-build-debug
+Testing
+debug

CMakeLists.txt

@@ -1,11 +1,20 @@
 cmake_minimum_required(VERSION 3.26)
-project(query)
+project(
+  query
+  VERSION 1.0.0
+  DESCRIPTION "SQL query fluent prototype for PostgreSQL, SQLite, MySQL and MSSQL"
+  LANGUAGES CXX
+)
 
 set(CMAKE_CXX_STANDARD 17)
 set(CMAKE_POSITION_INDEPENDENT_CODE ON)
 
 set(GCC_CLANG_COMMON_FLAGS "-Wall -Wconversion -Wextra -pedantic -ftemplate-backtrace-limit=0")
 
+if (WIN32)
+  add_compile_options(/Zc:preprocessor)
+endif()
+
 list(APPEND CMAKE_MODULE_PATH ${CMAKE_SOURCE_DIR}/cmake)
 
 find_package(ODBC REQUIRED)
@@ -13,6 +22,10 @@ find_package(SQLite3 REQUIRED)
 find_package(PostgreSQL REQUIRED)
 find_package(MySQL REQUIRED)
 
+message(STATUS "Found ODBC config ${ODBC_CONFIG}")
+message(STATUS "Adding ODBC include directory: ${ODBC_INCLUDE_DIRS}")
+message(STATUS "Adding ODBC libs: ${ODBC_LIBRARIES}")
+
 message(STATUS "Found SQLite3 ${SQLite3_VERSION}")
 message(STATUS "Adding SQLite3 include directory: ${SQLite3_INCLUDE_DIRS}")
 message(STATUS "Adding SQLite3 libs: ${SQLite3_LIBRARIES}")
@@ -29,6 +42,8 @@ message(STATUS "Relase flags ${CMAKE_CXX_FLAGS_RELEASE}")
 
 message(STATUS "Linker flags ${CMAKE_EXE_LINKER_FLAGS}")
 
+enable_testing()
+
 add_subdirectory(src)
 add_subdirectory(test)
 add_subdirectory(backends)

README.md

@@ -2,6 +2,8 @@
 
 A fluent sql query_context builder
 
+```MATADOR_BACKENDS_PATH=/home/sascha/Develop/query/cmake-build-debug/backends```
+
 Object definition
 ```cpp
 enum class Color {

Todo.md

@@ -3,6 +3,45 @@
 - Add is_valid() method to connection & connection_impl
 - Read in entity fields
 - Add special handling for update in backends
-- Add PostgreSQL backend
-- Add MySQL/MariaDB backend
 - Add ODBC/SQL Server backend
+
+
+Fetch eager strategies
+======================
+
+ONE TO ONE/MANY
+*person*             *address*
+- has one address    - belongs to person
+
+=> join "address" on "person.id" == "address.person_id"
+
+*address*             *person*
+- belongs to person   - has one address
+
+=> join "person" on "address.person_id" == "person.id"
+
+*book*               *author*
+- belongs to author  - has many books
+
+- => join "author" on "book.author_id" == "author.id"
+
+HAS MANY TO ONE (WITHOUT RELATION TABLE)
+
+*author*             *book*
+- has many books     - belongs to author
+
+- => join "book" on "author.id" == "book.author_id"
+
+if "has many" type has primary key & field "author_id"
+if table name belongs to entity template type?
+
+HAS MANY TO MANY (WITHOUT RELATION TABLE)
+
+*student*            *student_course*           *course*
+- has many courses   - belongs to student
+                     - belongs to course        - has many students
+
+=> join "student_course" on "student.id" == "student_course.student_id"
+   join "student_course" on "course.id" == "student_course.course_id"
+
+if has many type hasn't primary key (is relation table)

backends/mysql/CMakeLists.txt

@@ -20,6 +20,8 @@ set(SOURCES
 
 set(LIBRARY_TARGET matador-mysql)
 
+add_subdirectory(test)
+
 add_library(${LIBRARY_TARGET} MODULE ${SOURCES} ${HEADER})
 
 set_target_properties(${LIBRARY_TARGET}

backends/mysql/include/mysql_connection.hpp

@@ -37,7 +37,7 @@ public:
 
   size_t execute(const std::string &stmt) override;
 
-  sql::record describe(const std::string& table) override;
+  std::vector<sql::column_definition> describe(const std::string& table) override;
 
   bool exists(const std::string &schema_name, const std::string &table_name) override;
 

backends/mysql/include/mysql_parameter_binder.hpp

@@ -54,6 +54,8 @@ public:
   void bind(size_t pos, const std::string &string) override;
   void bind(size_t pos, const std::string &x, size_t size) override;
 
+  void bind(size_t pos, const utils::blob &blob) override;
+
   [[nodiscard]] std::vector<MYSQL_BIND>& bind_params();
 
 private:

backends/mysql/src/mysql_connection.cpp

@@ -90,12 +90,9 @@ sql::data_type_t to_type(enum_field_types type, unsigned int flags)
   }
 }
 
-utils::constraints to_options(unsigned int flags)
+utils::constraints to_constraints(unsigned int flags)
 {
   utils::constraints options{utils::constraints::NONE};
-  if (flags & NOT_NULL_FLAG) {
-    options |= utils::constraints::NOT_NULL;
-  }
   if (flags & PRI_KEY_FLAG) {
     options |= utils::constraints::PRIMARY_KEY;
   }
@@ -106,11 +103,49 @@ utils::constraints to_options(unsigned int flags)
   return options;
 }
 
+sql::null_option to_null_option(unsigned int flags)
+{
+  return flags & NOT_NULL_FLAG ? sql::null_option::NOT_NULL : sql::null_option::NULLABLE;
+}
+
 sql::data_type_t string2type(const std::string &type_string)
 {
-  //  if (strcmp(type_string.c_str(), "int")
+  if (strncmp(type_string.c_str(), "tinyint", 7) == 0) {
+    return sql::data_type_t::type_char;
+  } else if (strncmp(type_string.c_str(), "smallint", 8) == 0) {
+    if (strstr(type_string.c_str(), "unsigned") != nullptr) {
+      return sql::data_type_t::type_unsigned_short;
+    } else {
+      return sql::data_type_t::type_short;
+    }
+  } else if (strncmp(type_string.c_str(), "int", 3) == 0) {
+    if (strstr(type_string.c_str(), "unsigned") != nullptr) {
+      return sql::data_type_t::type_unsigned_int;
+    } else {
+      return sql::data_type_t::type_int;
+    }
+  } else if (strncmp(type_string.c_str(), "bigint", 6) == 0) {
+    if (strstr(type_string.c_str(), "unsigned") != nullptr) {
+      return sql::data_type_t::type_unsigned_long_long;
+    } else {
+      return sql::data_type_t::type_long_long;
+    }
+  } else if (strcmp(type_string.c_str(), "date") == 0) {
+    return sql::data_type_t::type_date;
+  } else if (strncmp(type_string.c_str(), "datetime", 8) == 0) {
+    return sql::data_type_t::type_time;
+  } else if (strcmp(type_string.c_str(), "float") == 0) {
+    return sql::data_type_t::type_float;
+  } else if (strcmp(type_string.c_str(), "double") == 0) {
+    return sql::data_type_t::type_double;
+  } else if (strncmp(type_string.c_str(), "varchar", 7) == 0) {
+    return sql::data_type_t::type_varchar;
+  } else if (strncmp(type_string.c_str(), "text", 4) == 0) {
+    return sql::data_type_t::type_text;
+  } else {
     return sql::data_type_t::type_unknown;
   }
+}
 
 struct type_info
 {
@@ -146,12 +181,13 @@ std::unique_ptr<sql::query_result_impl> mysql_connection::fetch(const std::strin
 
   auto field_count = mysql_num_fields(result);
   auto fields = mysql_fetch_fields(result);
-  sql::record prototype;
+  std::vector<sql::column_definition> prototype;
   for (unsigned i = 0; i < field_count; ++i) {
     auto type = to_type(fields[i].type, fields[i].flags);
-    auto options = to_options(fields[i].flags);
+    auto options = to_constraints(fields[i].flags);
+    auto null_opt = to_null_option(fields[i].flags);
 
-    prototype.append({fields[i].name, type, options});
+    prototype.emplace_back(fields[i].name, type, options, null_opt);
   }
 
   return std::move(std::make_unique<sql::query_result_impl>(std::make_unique<mysql_result_reader>(result, field_count), std::move(prototype)));
@@ -180,7 +216,7 @@ size_t mysql_connection::execute(const std::string &stmt)
   return mysql_affected_rows(mysql_.get());
 }
 
-sql::record mysql_connection::describe(const std::string &table)
+std::vector<sql::column_definition> mysql_connection::describe(const std::string &table)
 {
   std::string stmt("SHOW COLUMNS FROM " + table);
 
@@ -194,23 +230,19 @@ sql::record mysql_connection::describe(const std::string &table)
   }
 
   mysql_result_reader reader(result, mysql_num_fields(result));
-  sql::record prototype;
+  std::vector<sql::column_definition> prototype;
   while (reader.fetch()) {
 
     char *end = nullptr;
-    // Todo: Handle error
+    std::string name = reader.column(0);
-    auto index = strtoul(reader.column(0), &end, 10);
-    std::string name = reader.column(1);
 
-    // Todo: extract size
+    auto typeinfo = determine_type_info(reader.column(1));
-    auto typeinfo = determine_type_info(reader.column(2));
     end = nullptr;
-    utils::constraints options{};
+    sql::null_option null_opt{sql::null_option::NULLABLE};
-    if (strtoul(reader.column(4), &end, 10) == 0) {
+    if (strtoul(reader.column(2), &end, 10) == 0) {
-      options = utils::constraints::NOT_NULL;
+      null_opt = sql::null_option::NOT_NULL;
     }
-    // f.default_value(res->column(4));
+    prototype.push_back({name, typeinfo.type, {typeinfo.size}, null_opt, prototype.size()});
-    prototype.append({name, typeinfo.type, {typeinfo.size, options}});
   }
 
   return prototype;

backends/mysql/src/mysql_dialect.cpp

@@ -7,14 +7,11 @@
   using namespace matador::sql;
   const static dialect d = dialect_builder::builder()
     .create()
-    .with_placeholder_func([](size_t index) {
-      return "$" + std::to_string(index);
-    })
     .with_token_replace_map({
                               {dialect::token_t::START_QUOTE, "`"},
                               {dialect::token_t::END_QUOTE, "`"},
                             })
-    .with_default_schema_name("public")
+    .with_default_schema_name("")
     .build();
   return &d;
 }

backends/mysql/src/mysql_parameter_binder.cpp

@@ -90,6 +90,7 @@ void bind_value(enum_field_types type, const char *value, size_t, MYSQL_BIND &bi
 
 mysql_parameter_binder::mysql_parameter_binder(size_t size)
 : bind_params_(size)
+, is_null_vector(size)
 , info_(size)
 {}
 
@@ -178,6 +179,11 @@ void mysql_parameter_binder::bind(size_t pos, const std::string &str, size_t siz
   detail::bind_value(MYSQL_TYPE_VAR_STRING, str.data(), size, bind_params_[pos], is_null_vector[pos].is_null);
 }
 
+void mysql_parameter_binder::bind(size_t pos, const utils::blob &blob)
+{
+
+}
+
 std::vector<MYSQL_BIND> &mysql_parameter_binder::bind_params()
 {
   return bind_params_;

backends/mysql/test/CMakeLists.txt

@@ -0,0 +1,46 @@
+Include(FetchContent)
+
+FetchContent_Declare(
+  Catch2
+  GIT_REPOSITORY https://github.com/catchorg/Catch2.git
+  GIT_TAG        v3.5.4 # or a later release
+)
+
+FetchContent_MakeAvailable(Catch2)
+
+list(APPEND CMAKE_MODULE_PATH ${catch2_SOURCE_DIR}/extras)
+include(CTest)
+include(Catch)
+
+set(MYSQL_CONNECTION_STRING "mysql://test:test123!@127.0.0.1:3306/matador_test")
+
+configure_file(Connection.hpp.in ${PROJECT_BINARY_DIR}/backends/mysql/test/connection.hpp @ONLY IMMEDIATE)
+
+message(STATUS "mysql connection string: ${MYSQL_CONNECTION_STRING}")
+
+set(TEST_SOURCES
+  ../../tests/QueryTest.cpp
+  ../../tests/QueryTest.cpp
+  ../../tests/ConnectionTest.cpp
+  ../../tests/QueryRecordTest.cpp
+  ../../tests/StatementTest.cpp
+  ../../tests/TypeTraitsTest.cpp
+  ../../tests/StatementCacheTest.cpp
+  ../../tests/SessionTest.cpp)
+
+set(LIBRARY_TEST_TARGET mysql_tests)
+
+add_executable(${LIBRARY_TEST_TARGET} ${TEST_SOURCES})
+
+target_link_libraries(${LIBRARY_TEST_TARGET} PRIVATE
+  Catch2::Catch2WithMain
+  matador
+  ${CMAKE_DL_LIBS}
+  ${MySQL_LIBRARY})
+
+target_include_directories(${LIBRARY_TEST_TARGET}
+  PUBLIC $<BUILD_INTERFACE:${PROJECT_SOURCE_DIR}>/include
+  PRIVATE $<BUILD_INTERFACE:${PROJECT_SOURCE_DIR}>/test
+  PRIVATE ${CMAKE_CURRENT_BINARY_DIR})
+
+catch_discover_tests(${LIBRARY_TEST_TARGET} TEST_SUFFIX " (MySQL)")

backends/mysql/test/Connection.hpp.in

@@ -0,0 +1,8 @@
+#ifndef MYSQL_CONNECTION_HPP
+#define MYSQL_CONNECTION_HPP
+
+namespace matador::test::connection {
+ const char* const dns = "@MYSQL_CONNECTION_STRING@";
+}
+
+#endif /*SQLITE_CONNECTION_HPP*/

backends/postgres/CMakeLists.txt

@@ -18,6 +18,8 @@ set(SOURCES
 
 set(LIBRARY_TARGET matador-postgres)
 
+add_subdirectory(test)
+
 add_library(${LIBRARY_TARGET} MODULE ${SOURCES} ${HEADER})
 
 set_target_properties(${LIBRARY_TARGET}

backends/postgres/include/postgres_connection.hpp

@@ -33,7 +33,7 @@ public:
 
   size_t execute(const std::string &stmt) override;
 
-  sql::record describe(const std::string& table) override;
+  std::vector<sql::column_definition> describe(const std::string& table) override;
 
   bool exists(const std::string &schema_name, const std::string &table_name) override;
 

backends/postgres/include/postgres_parameter_binder.h

@@ -30,7 +30,9 @@ public:
   void bind(size_t pos, const std::string &string) override;
   void bind(size_t pos, const std::string &x, size_t size) override;
 
-  const std::vector<const char*>& params() const;
+  void bind(size_t pos, const utils::blob &blob) override;
+
+  [[nodiscard]] const std::vector<const char*>& params() const;
 
 private:
   std::vector<std::string> strings_;

backends/postgres/src/postgres_connection.cpp

@@ -25,9 +25,10 @@ void postgres_connection::open()
 
   conn_ = PQconnectdb(connection.c_str());
   if (PQstatus(conn_) == CONNECTION_BAD) {
-    const auto msg = PQerrorMessage(conn_);
+    const std::string msg = PQerrorMessage(conn_);
     PQfinish(conn_);
-    throw_postgres_error(msg, "postgres");
+    conn_ = nullptr;
+    throw_postgres_error(msg.c_str(), "postgres");
   }
 }
 
@@ -50,14 +51,13 @@ std::unique_ptr<sql::query_result_impl> postgres_connection::fetch(const std::st
 
   throw_postgres_error(res, conn_, "postgres", stmt);
 
-  sql::record prototype;
+  std::vector<sql::column_definition> prototype;
   auto num_col = PQnfields(res);
   for (int i = 0; i < num_col; ++i) {
     const char *col_name = PQfname(res, i);
     auto type = PQftype(res, i);
     auto size = PQfmod(res, i);
-//    std::cout << "column " << col_name << ", type " << type << " (size: " << size << ")\n";
+    prototype.emplace_back(col_name);
-    prototype.append({col_name});
   }
   return std::move(std::make_unique<sql::query_result_impl>(std::make_unique<postgres_result_reader>(res), std::move(prototype)));
 }
@@ -65,7 +65,7 @@ std::unique_ptr<sql::query_result_impl> postgres_connection::fetch(const std::st
 std::string postgres_connection::generate_statement_name(const sql::query_context &query)
 {
   std::stringstream name;
-  name << query.table_name << "_" << query.command_name;
+  name << query.table.name << "_" << query.command_name;
   auto result = postgres_connection::statement_name_map_.find(name.str());
 
   if (result == postgres_connection::statement_name_map_.end()) {
@@ -130,7 +130,7 @@ sql::data_type_t string2type(const char *type)
   }
 }
 
-sql::record postgres_connection::describe(const std::string &table)
+std::vector<sql::column_definition> postgres_connection::describe(const std::string &table)
 {
   std::string stmt(
     "SELECT ordinal_position, column_name, udt_name, data_type, is_nullable, column_default FROM information_schema.columns WHERE table_schema='public' AND table_name='" + table + "'");
@@ -140,22 +140,22 @@ sql::record postgres_connection::describe(const std::string &table)
   throw_postgres_error(res, conn_, "postgres", stmt);
 
   postgres_result_reader reader(res);
-  sql::record prototype;
+  std::vector<sql::column_definition> prototype;
   while (reader.fetch()) {
     char *end = nullptr;
     // Todo: Handle error
-    auto index = strtoul(reader.column(0), &end, 10);
+    auto index = strtoul(reader.column(0), &end, 10) - 1;
     std::string name = reader.column(1);
 
     // Todo: extract size
     auto type = (string2type(reader.column(2)));
     end = nullptr;
-    utils::constraints options{};
+    sql::null_option null_opt{sql::null_option::NULLABLE};
     if (strtoul(reader.column(4), &end, 10) == 0) {
-      options = utils::constraints::NOT_NULL;
+      null_opt = sql::null_option::NOT_NULL;
     }
     // f.default_value(res->column(4));
-    prototype.append({name, type, {options}});
+    prototype.emplace_back(name, type, utils::null_attributes, null_opt, index);
   }
 
   return std::move(prototype);

backends/postgres/src/postgres_dialect.cpp

@@ -2,13 +2,20 @@
 
 #include "matador/sql/dialect_builder.hpp"
 
-[[maybe_unused]] const matador::sql::dialect* get_dialect() {
+[[maybe_unused]] const matador::sql::dialect *get_dialect()
+{
   using namespace matador::sql;
   const static dialect d = dialect_builder::builder()
     .create()
     .with_placeholder_func([](size_t index) {
       return "$" + std::to_string(index);
     })
+    .with_token_replace_map({
+                          {dialect::token_t::BEGIN_BINARY_DATA, "E'\\"}
+                          })
+    .with_data_type_replace_map({
+                                  {data_type_t::type_blob, "BYTEA"}
+                                })
     .with_default_schema_name("public")
     .build();
   return &d;

backends/postgres/src/postgres_error.cpp

@@ -22,8 +22,11 @@ void throw_postgres_error(PGconn *db, const std::string &source)
 
 void throw_postgres_error(PGresult *res, PGconn *db, const std::string &source, const std::string &sql)
 {
-  if (res == nullptr ||
+  if (res == nullptr) {
-      (PQresultStatus(res) != PGRES_COMMAND_OK &&
+    std::stringstream msg;
+    msg << "postgres error (" << source << ", " << PQerrorMessage(db) << ": " << sql;
+    throw std::logic_error(msg.str());
+  } else if ((PQresultStatus(res) != PGRES_COMMAND_OK &&
               PQresultStatus(res) != PGRES_TUPLES_OK)) {
     std::stringstream msg;
     msg << "postgres error (" << source << ", " << PQresultErrorField(res, PG_DIAG_SQLSTATE) << ") " << PQerrorMessage(db) << ": " << sql;

backends/postgres/src/postgres_parameter_binder.cpp

@@ -134,6 +134,11 @@ void postgres_parameter_binder::bind(size_t pos, const std::string &str, size_t
   bind(pos, str);
 }
 
+void postgres_parameter_binder::bind(size_t pos, const utils::blob &blob)
+{
+  params_[pos] = "";
+}
+
 const std::vector<const char *> &postgres_parameter_binder::params() const
 {
   return params_;

backends/postgres/test/CMakeLists.txt

@@ -0,0 +1,45 @@
+Include(FetchContent)
+
+FetchContent_Declare(
+  Catch2
+  GIT_REPOSITORY https://github.com/catchorg/Catch2.git
+  GIT_TAG        v3.5.4 # or a later release
+)
+
+FetchContent_MakeAvailable(Catch2)
+
+list(APPEND CMAKE_MODULE_PATH ${catch2_SOURCE_DIR}/extras)
+include(CTest)
+include(Catch)
+
+set(POSTGRES_CONNECTION_STRING "postgres://test:test123@127.0.0.1:15432/test")
+
+configure_file(Connection.hpp.in ${PROJECT_BINARY_DIR}/backends/postgres/test/connection.hpp @ONLY IMMEDIATE)
+
+message(STATUS "postgresql connection string: ${POSTGRES_CONNECTION_STRING}")
+
+set(TEST_SOURCES
+  ../../tests/QueryTest.cpp
+  ../../tests/ConnectionTest.cpp
+  ../../tests/QueryRecordTest.cpp
+  ../../tests/StatementTest.cpp
+  ../../tests/TypeTraitsTest.cpp
+  ../../tests/StatementCacheTest.cpp
+  ../../tests/SessionTest.cpp)
+
+set(LIBRARY_TEST_TARGET postgres_tests)
+
+add_executable(${LIBRARY_TEST_TARGET} ${TEST_SOURCES})
+
+target_link_libraries(${LIBRARY_TEST_TARGET} PRIVATE
+  Catch2::Catch2WithMain
+  matador
+  ${CMAKE_DL_LIBS}
+  ${PostgreSQL_LIBRARY})
+
+target_include_directories(${LIBRARY_TEST_TARGET}
+  PUBLIC $<BUILD_INTERFACE:${PROJECT_SOURCE_DIR}>/include
+  PRIVATE $<BUILD_INTERFACE:${PROJECT_SOURCE_DIR}>/test
+  PRIVATE ${CMAKE_CURRENT_BINARY_DIR})
+
+catch_discover_tests(${LIBRARY_TEST_TARGET} TEST_SUFFIX " (PostgreSQL)")

backends/postgres/test/Connection.hpp.in

@@ -0,0 +1,8 @@
+#ifndef POSTGRES_CONNECTION_HPP
+#define POSTGRES_CONNECTION_HPP
+
+namespace matador::test::connection {
+ const char* const dns = "@POSTGRES_CONNECTION_STRING@";
+}
+
+#endif /*POSTGRES_CONNECTION_HPP*/

backends/sqlite/CMakeLists.txt

@@ -20,6 +20,8 @@ set(SOURCES
 
 set(LIBRARY_TARGET matador-sqlite)
 
+add_subdirectory(test)
+
 add_library(${LIBRARY_TARGET} MODULE ${SOURCES} ${HEADER})
 
 set_target_properties(${LIBRARY_TARGET}

backends/sqlite/include/sqlite_connection.hpp

@@ -33,14 +33,14 @@ public:
 
   size_t execute(const std::string &stmt) override;
 
-  sql::record describe(const std::string& table) override;
+  std::vector<sql::column_definition> describe(const std::string& table) override;
 
   bool exists(const std::string &schema_name, const std::string &table_name) override;
 
 private:
   struct fetch_context
   {
-    sql::record prototype;
+    std::vector<sql::column_definition> prototype;
     sqlite_result_reader::rows rows;
   };
 

backends/sqlite/include/sqlite_parameter_binder.h

@@ -32,7 +32,7 @@ public:
   void bind(size_t pos, const char *str, size_t size) override;
   void bind(size_t pos, const std::string &str) override;
   void bind(size_t pos, const std::string &str, size_t size) override;
-
+  void bind(size_t pos, const utils::blob &blob) override;
 private:
   sqlite3 *db_{nullptr};
   sqlite3_stmt *stmt_{nullptr};

backends/sqlite/include/sqlite_prepared_result_reader.hpp

@@ -32,7 +32,7 @@ public:
   void read_value(const char *id, size_t index, char *value, size_t s) override;
   void read_value(const char *id, size_t index, std::string &value) override;
   void read_value(const char *id, size_t index, std::string &value, size_t s) override;
-  void read_value(const char *id, size_t index, sql::any_type &value, sql::data_type_t type, size_t size) override;
+  void read_value(const char *id, size_t index, sql::value &val, size_t size) override;
 
 private:
   sqlite3 *db_{nullptr};

backends/sqlite/src/sqlite_connection.cpp

@@ -65,7 +65,7 @@ int sqlite_connection::parse_result(void* param, int column_count, char** values
 
   if (context->prototype.empty()) {
     for(int i = 0; i < column_count; ++i) {
-      context->prototype.append(sql::column{columns[i]});
+      context->prototype.emplace_back(columns[i]);
     }
   }
 
@@ -144,12 +144,12 @@ sql::data_type_t string2type(const char *type)
   }
 }
 
-sql::record sqlite_connection::describe(const std::string& table)
+std::vector<sql::column_definition> sqlite_connection::describe(const std::string& table)
 {
   const auto result = fetch_internal("PRAGMA table_info(" + table + ")");
 
   sqlite_result_reader reader(result.rows, result.prototype.size());
-  sql::record prototype;
+  std::vector<sql::column_definition> prototype;
   while (reader.fetch()) {
     char *end = nullptr;
     // Todo: add index to column
@@ -158,12 +158,12 @@ sql::record sqlite_connection::describe(const std::string& table)
 
     auto type = (string2type(reader.column(2)));
     end = nullptr;
-    utils::constraints options{};
+    sql::null_option null_opt{sql::null_option::NULLABLE};
     if (strtoul(reader.column(3), &end, 10) == 0) {
-      options = utils::constraints::NOT_NULL;
+      null_opt = sql::null_option::NOT_NULL;
     }
     // f.default_value(res->column(4));
-    prototype.append({name, type, {options}});
+    prototype.emplace_back(name, type, utils::null_attributes, null_opt, index);
   }
 
   return std::move(prototype);

backends/sqlite/src/sqlite_parameter_binder.cpp

@@ -118,4 +118,9 @@ void sqlite_parameter_binder::bind(size_t pos, const std::string &x, size_t size
   throw_sqlite_error(ret, db_, "sqlite3_bind_text");
 }
 
+void sqlite_parameter_binder::bind(size_t pos, const utils::blob &blob)
+{
+
+}
+
 }

backends/sqlite/src/sqlite_prepared_result_reader.cpp

@@ -107,8 +107,8 @@ void sqlite_prepared_result_reader::read_value(const char *id, size_t index, std
   query_result_reader::read_value(id, index, value, s);
 }
 
-void sqlite_prepared_result_reader::read_value(const char *id, size_t index, sql::any_type &value, sql::data_type_t type, size_t size)
+void sqlite_prepared_result_reader::read_value(const char *id, size_t index, sql::value &val, size_t size)
 {
-  query_result_reader::read_value(id, index, value, type, size);
+  query_result_reader::read_value(id, index, val, size);
 }
 }

backends/sqlite/test/CMakeLists.txt

@@ -0,0 +1,46 @@
+Include(FetchContent)
+
+FetchContent_Declare(
+  Catch2
+  GIT_REPOSITORY https://github.com/catchorg/Catch2.git
+  GIT_TAG        v3.5.4 # or a later release
+)
+
+FetchContent_MakeAvailable(Catch2)
+
+list(APPEND CMAKE_MODULE_PATH ${catch2_SOURCE_DIR}/extras)
+include(CTest)
+include(Catch)
+
+set(SQLITE_CONNECTION_STRING "sqlite://test.db")
+
+configure_file(Connection.hpp.in ${PROJECT_BINARY_DIR}/backends/sqlite/test/connection.hpp @ONLY IMMEDIATE)
+
+message(STATUS "sqlite connection string: ${SQLITE_CONNECTION_STRING}")
+
+set(TEST_SOURCES
+  ../../tests/QueryTest.cpp
+  ../../tests/QueryTest.cpp
+  ../../tests/ConnectionTest.cpp
+  ../../tests/QueryRecordTest.cpp
+  ../../tests/StatementTest.cpp
+  ../../tests/TypeTraitsTest.cpp
+  ../../tests/StatementCacheTest.cpp
+  ../../tests/SessionTest.cpp)
+
+set(LIBRARY_TEST_TARGET sqlite_tests)
+
+add_executable(${LIBRARY_TEST_TARGET} ${TEST_SOURCES})
+
+target_link_libraries(${LIBRARY_TEST_TARGET} PRIVATE
+  Catch2::Catch2WithMain
+  matador
+  ${CMAKE_DL_LIBS}
+  ${SQLite3_LIBRARY})
+
+target_include_directories(${LIBRARY_TEST_TARGET}
+  PUBLIC $<BUILD_INTERFACE:${PROJECT_SOURCE_DIR}>/include
+  PRIVATE $<BUILD_INTERFACE:${PROJECT_SOURCE_DIR}>/test
+  PRIVATE ${CMAKE_CURRENT_BINARY_DIR})
+
+catch_discover_tests(${LIBRARY_TEST_TARGET} TEST_SUFFIX " (SQLite3)")

backends/sqlite/test/Connection.hpp.in

@@ -0,0 +1,8 @@
+#ifndef SQLITE_CONNECTION_HPP
+#define SQLITE_CONNECTION_HPP
+
+namespace matador::test::connection {
+ const char* const dns = "@SQLITE_CONNECTION_STRING@";
+}
+
+#endif /*SQLITE_CONNECTION_HPP*/

backends/tests/ConnectionTest.cpp

@@ -0,0 +1,19 @@
+#include "catch2/catch_test_macros.hpp"
+
+#include "matador/sql/connection.hpp"
+
+#include "connection.hpp"
+
+using namespace matador::sql;
+
+TEST_CASE("Create connection test", "[connection]") {
+
+  connection c(matador::test::connection::dns);
+  REQUIRE(!c.is_open());
+
+  c.open();
+  REQUIRE(c.is_open());
+
+  c.close();
+  REQUIRE(!c.is_open());
+}

backends/tests/QueryRecordTest.cpp

@@ -0,0 +1,402 @@
+#include <catch2/catch_test_macros.hpp>
+
+#include "matador/sql/column.hpp"
+#include "matador/sql/condition.hpp"
+#include "matador/sql/connection.hpp"
+#include "matador/sql/query_builder.hpp"
+
+#include "connection.hpp"
+
+#include <list>
+
+class QueryRecordFixture
+{
+public:
+  QueryRecordFixture()
+  : db(matador::test::connection::dns)
+  , schema(db.dialect().default_schema_name())
+  {
+    db.open();
+  }
+  ~QueryRecordFixture() {
+    drop_table_if_exists("flight");
+    drop_table_if_exists("airplane");
+    drop_table_if_exists("person");
+    drop_table_if_exists("quotes");
+  }
+
+protected:
+  matador::sql::connection db;
+  matador::sql::schema schema;
+
+private:
+  void drop_table_if_exists(const std::string &table_name) {
+    if (db.exists(table_name)) {
+      db.query(schema).drop().table(table_name).execute();
+    }
+  }
+};
+
+using namespace matador::sql;
+
+TEST_CASE_METHOD(QueryRecordFixture, "Create and drop table statement", "[session][record]")
+{
+  REQUIRE(!db.exists("person"));
+  db.query(schema).create()
+  .table("person", {
+    make_pk_column<unsigned long>("id"),
+    make_column<std::string>("name", 255),
+    make_column<unsigned short>("age")
+  })
+  .execute();
+
+  REQUIRE(db.exists("person"));
+
+  db.query(schema).drop()
+  .table("person")
+  .execute();
+
+  REQUIRE(!db.exists("person"));
+}
+
+TEST_CASE_METHOD(QueryRecordFixture, "Create and drop table statement with foreign key", "[session][record]")
+{
+  db.query(schema).create()
+  .table("airplane", {
+    make_pk_column<unsigned long>("id"),
+    make_column<std::string>("brand", 255),
+    make_column<std::string>("model", 255),
+  })
+  .execute();
+
+  REQUIRE(db.exists("airplane"));
+
+  db.query(schema).create()
+  .table("flight", {
+    make_pk_column<unsigned long>("id"),
+    make_fk_column<unsigned long>("airplane_id", "airplane", "id"),
+    make_column<std::string>("pilot_name", 255),
+  })
+  .execute();
+
+  REQUIRE(db.exists("flight"));
+
+  db.query(schema).drop()
+  .table("flight")
+  .execute();
+
+  REQUIRE(!db.exists("flight"));
+
+  db.query(schema).drop()
+  .table("airplane")
+  .execute();
+
+  REQUIRE(!db.exists("airplane"));
+}
+
+TEST_CASE_METHOD(QueryRecordFixture, "Execute insert record statement", "[session][record]")
+{
+  db.query(schema).create()
+  .table("person", {
+    make_pk_column<unsigned long>("id"),
+    make_column<std::string>("name", 255),
+    make_column<unsigned short>("age")
+  })
+  .execute();
+
+  auto res = db.query(schema).insert()
+  .into("person", {"id", "name", "age"})
+  .values({7, "george", 45})
+  .execute();
+
+  REQUIRE(res == 1);
+
+  auto result = db.query(schema).select({"id", "name", "age"})
+  .from("person")
+  .fetch_all();
+
+  for (const auto &i: result) {
+    REQUIRE(i.size() == 3);
+    REQUIRE(i.at(0).name() == "id");
+    //    REQUIRE(i.at(0).type() == data_type_t::type_long_long);
+    REQUIRE(i.at(0).template as<long long>() == 7);
+    REQUIRE(i.at(1).name() == "name");
+    //    REQUIRE(i.at(1).type() == data_type_t::type_varchar);
+    REQUIRE(i.at(1).template as<std::string>() == "george");
+    REQUIRE(i.at(2).name() == "age");
+    //    REQUIRE(i.at(2).type() == matador::sql::data_type_t::type_int);
+    REQUIRE(i.at(2).template as<int>() == 45);
+  }
+
+  db.query(schema).drop()
+  .table("person")
+  .execute();
+}
+
+TEST_CASE_METHOD(QueryRecordFixture, "Execute insert record statement with foreign key", "[session][record]")
+{
+  db.query(schema).create()
+  .table("airplane", {
+    make_pk_column<unsigned long>("id"),
+    make_column<std::string>("brand", 255),
+    make_column<std::string>("model", 255),
+  })
+  .execute();
+
+  db.query(schema).create()
+  .table("flight", {
+    make_pk_column<unsigned long>("id"),
+    make_fk_column<unsigned long>("airplane_id", "airplane", "id"),
+    make_column<std::string>("pilot_name", 255),
+  })
+  .execute();
+
+  auto res = db.query(schema).insert().into("airplane", {"id", "brand", "model"}).values({1, "Airbus", "A380"}).execute();
+  REQUIRE(res == 1);
+
+  res = db.query(schema).insert().into("airplane", {"id", "brand", "model"}).values({2, "Boeing", "707"}).execute();
+  REQUIRE(res == 1);
+
+  res = db.query(schema).insert().into("airplane", {"id", "brand", "model"}).values({3, "Boeing", "747"}).execute();
+  REQUIRE(res == 1);
+
+  auto count = db.query(schema).select({count_all()}).from("airplane").fetch_value<int>();
+  REQUIRE(count == 3);
+
+  res = db.query(schema).insert().into("flight", {"id", "airplane_id", "pilot_name"}).values({4, 1, "George"}).execute();
+  REQUIRE(res == 1);
+
+  db.query(schema).drop().table("flight").execute();
+  db.query(schema).drop().table("airplane").execute();
+
+  REQUIRE(!db.exists("flight"));
+  REQUIRE(!db.exists("airplane"));
+}
+
+TEST_CASE_METHOD(QueryRecordFixture, "Execute update record statement", "[session][record]")
+{
+  db.query(schema).create()
+  .table("person", {
+    make_pk_column<unsigned long>("id"),
+    make_column<std::string>("name", 255),
+    make_column<unsigned short>("age")
+  })
+  .execute();
+
+  auto res = db.query(schema).insert()
+  .into("person", {"id", "name", "age"})
+  .values({7, "george", 45})
+  .execute();
+
+  REQUIRE(res == 1);
+
+  res = db.query(schema).update("person")
+  .set({{"id",   7},
+        {"name", "jane"},
+        {"age",  35}})
+  .where("id"_col == 7)
+  .execute();
+
+  REQUIRE(res == 1);
+
+  auto result = db.query(schema).select({"id", "name", "age"})
+  .from("person")
+  .fetch_all();
+
+  for (const auto &i: result) {
+    REQUIRE(i.size() == 3);
+    REQUIRE(i.at(0).name() == "id");
+    REQUIRE(i.at(0).is_integer());
+    REQUIRE(i.at(0).as<long long>() == 7);
+    REQUIRE(i.at(1).name() == "name");
+    REQUIRE(i.at(1).is_varchar());
+    REQUIRE(i.at(1).as<std::string>() == "jane");
+    REQUIRE(i.at(2).name() == "age");
+    REQUIRE(i.at(2).is_integer());
+    REQUIRE(i.at(2).as<int>() == 35);
+  }
+
+  db.query(schema).drop().table("person").execute();
+}
+
+TEST_CASE_METHOD(QueryRecordFixture, "Execute select statement", "[session][record]")
+{
+  db.query(schema).create()
+  .table("person", {
+    make_pk_column<unsigned long>("id"),
+    make_column<std::string>("name", 255),
+    make_column<unsigned short>("age")
+  })
+  .execute();
+
+  auto res = db.query(schema).insert().into("person", {"id", "name", "age"}).values({1, "george", 45}).execute();
+  REQUIRE(res == 1);
+  res = db.query(schema).insert().into("person", {"id", "name", "age"}).values({2, "jane", 32}).execute();
+  REQUIRE(res == 1);
+  res = db.query(schema).insert().into("person", {"id", "name", "age"}).values({3, "michael", 67}).execute();
+  REQUIRE(res == 1);
+  res = db.query(schema).insert().into("person", {"id", "name", "age"}).values({4, "bob", 13}).execute();
+  REQUIRE(res == 1);
+
+  auto result = db.query(schema).select({"id", "name", "age"})
+  .from("person")
+  .fetch_all();
+
+  std::list<std::string> expected_names{"george", "jane", "michael", "bob"};
+  for (const auto &p: result) {
+    REQUIRE(p.at(1).str() == expected_names.front());
+    expected_names.pop_front();
+  }
+  REQUIRE(expected_names.empty());
+
+  auto rec = db.query(schema).select({"id", "name", "age"})
+  .from("person")
+  .fetch_one();
+  REQUIRE(rec.has_value());
+  REQUIRE(rec->at(1).str() == "george");
+
+  auto name = db.query(schema).select({"name"})
+  .from("person")
+  .fetch_value<std::string>();
+  REQUIRE(name == "george");
+
+  db.query(schema).drop().table("person").execute();
+}
+
+TEST_CASE_METHOD(QueryRecordFixture, "Execute select statement with order by", "[session][record]")
+{
+  db.query(schema).create()
+  .table("person", {
+    make_pk_column<unsigned long>("id"),
+    make_column<std::string>("name", 255),
+    make_column<unsigned short>("age")
+  })
+  .execute();
+
+  auto res = db.query(schema).insert().into("person", {"id", "name", "age"}).values({1, "george", 45}).execute();
+  REQUIRE(res == 1);
+  res = db.query(schema).insert().into("person", {"id", "name", "age"}).values({2, "jane", 32}).execute();
+  REQUIRE(res == 1);
+  res = db.query(schema).insert().into("person", {"id", "name", "age"}).values({3, "michael", 67}).execute();
+  REQUIRE(res == 1);
+  res = db.query(schema).insert().into("person", {"id", "name", "age"}).values({4, "bob", 13}).execute();
+  REQUIRE(res == 1);
+
+  auto result = db.query(schema).select({"id", "name", "age"})
+  .from("person")
+  .order_by("name").asc()
+  .fetch_all();
+
+  std::list<std::string> expected_names{"bob", "george", "jane", "michael"};
+  for (const auto &p: result) {
+    REQUIRE(p.at(1).str() == expected_names.front());
+    expected_names.pop_front();
+  }
+  REQUIRE(expected_names.empty());
+
+  db.query(schema).drop().table("person").execute();
+}
+
+TEST_CASE_METHOD(QueryRecordFixture, "Execute select statement with group by and order by", "[session][record]")
+{
+  db.query(schema).create()
+  .table("person", {
+    make_pk_column<unsigned long>("id"),
+    make_column<std::string>("name", 255),
+    make_column<unsigned short>("age")
+  })
+  .execute();
+
+  auto res = db.query(schema).insert().into("person", {"id", "name", "age"}).values({1, "george", 45}).execute();
+  REQUIRE(res == 1);
+  res = db.query(schema).insert().into("person", {"id", "name", "age"}).values({2, "jane", 45}).execute();
+  REQUIRE(res == 1);
+  res = db.query(schema).insert().into("person", {"id", "name", "age"}).values({3, "michael", 13}).execute();
+  REQUIRE(res == 1);
+  res = db.query(schema).insert().into("person", {"id", "name", "age"}).values({4, "bob", 13}).execute();
+  REQUIRE(res == 1);
+  res = db.query(schema).insert().into("person", {"id", "name", "age"}).values({5, "charlie", 67}).execute();
+  REQUIRE(res == 1);
+
+  auto result = db.query(schema).select({count("age").as("age_count"), "age"})
+  .from("person")
+  .group_by("age")
+  .order_by("age_count").desc()
+  .fetch_all();
+
+  std::list<std::pair<int, int>> expected_values{{2, 45},
+                                                 {2, 13},
+                                                 {1, 67}};
+  for (const auto &r: result) {
+    REQUIRE(r.at(0).as<int>() == expected_values.front().first);
+    REQUIRE(r.at(1).as<int>() == expected_values.front().second);
+    expected_values.pop_front();
+  }
+
+  db.query(schema).drop().table("person").execute();
+}
+
+TEST_CASE_METHOD(QueryRecordFixture, "Execute delete statement", "[session][record]")
+{
+  db.query(schema).create()
+  .table("person", {
+    make_pk_column<unsigned long>("id"),
+    make_column<std::string>("name", 255),
+    make_column<unsigned short>("age")
+  }).execute();
+
+  auto res = db.query(schema).insert().into("person", {"id", "name", "age"}).values({1, "george", 45}).execute();
+  REQUIRE(res == 1);
+  res = db.query(schema).insert().into("person", {"id", "name", "age"}).values({2, "jane", 45}).execute();
+  REQUIRE(res == 1);
+
+  auto count = db.query(schema).select({count_all()}).from("person").fetch_value<int>();
+  REQUIRE(count == 2);
+
+  res = db.query(schema).remove()
+  .from("person")
+  .where("id"_col == 1)
+  .execute();
+
+  REQUIRE(res == 1);
+
+  count = db.query(schema).select({count_all()}).from("person").fetch_value<int>();
+  REQUIRE(count == 1);
+
+  db.query(schema).drop().table("person").execute();
+}
+
+TEST_CASE_METHOD(QueryRecordFixture, "Test quoted identifier", "[session][record]") {
+  db.query(schema).create()
+  .table("quotes", {
+    make_column<std::string>("from", 255),
+    make_column<std::string>("to", 255)
+  }).execute();
+
+  // check table description
+  std::vector<std::string> columns = { "from", "to"};
+  std::vector<data_type_t> types = {data_type_t::type_varchar, data_type_t::type_varchar};
+  auto fields = db.describe("quotes");
+
+  for (const auto &field : fields) {
+    REQUIRE(field.name() == columns[field.index()]);
+    REQUIRE(field.type() == types[field.index()]);
+  }
+
+  db.query(schema).insert().into("quotes", {"from", "to"}).values({"Berlin", "London"}).execute();
+
+  auto res = db.query(schema).select({"from", "to"}).from("quotes").fetch_one();
+
+  REQUIRE(res.has_value());
+  REQUIRE("Berlin" == res->at("from").str());
+  REQUIRE("London" == res->at("to").str());
+
+  db.query(schema).update("quotes").set({{"from", "Hamburg"}, {"to", "New York"}}).where("from"_col == "Berlin").execute();
+
+  res = db.query(schema).select({"from", "to"}).from("quotes").fetch_one();
+
+  REQUIRE("Hamburg" == res->at("from").str());
+  REQUIRE("New York" == res->at("to").str());
+
+  db.query(schema).drop().table("quotes").execute();
+}

backends/tests/QueryTest.cpp

@@ -0,0 +1,535 @@
+#include "catch2/catch_test_macros.hpp"
+
+#include "matador/sql/column_definition.hpp"
+#include "matador/sql/condition.hpp"
+#include "matador/sql/query_builder.hpp"
+#include "matador/sql/session.hpp"
+
+#include "connection.hpp"
+
+#include "models/airplane.hpp"
+#include "models/flight.hpp"
+#include "models/person.hpp"
+#include "models/recipe.hpp"
+
+#include <iostream>
+
+using namespace matador::sql;
+using namespace matador::test;
+
+class QueryFixture
+{
+public:
+  QueryFixture()
+  : db(matador::test::connection::dns)
+  , schema(db.dialect().default_schema_name())
+  {
+    db.open();
+  }
+
+  ~QueryFixture()
+  {
+    drop_table_if_exists("flight");
+    drop_table_if_exists("airplane");
+    drop_table_if_exists("person");
+    drop_table_if_exists("recipe_ingredients");
+    drop_table_if_exists("recipes");
+    drop_table_if_exists("ingredients");
+  }
+
+protected:
+  matador::sql::connection db;
+  matador::sql::schema schema;
+
+private:
+  void drop_table_if_exists(const std::string &table_name)
+  {
+    if (db.exists(table_name)) {
+      db.query(schema).drop().table(table_name).execute();
+    }
+  }
+};
+
+TEST_CASE_METHOD(QueryFixture, "Create table with foreign key relation", "[session]")
+{
+  schema.attach<airplane>("airplane");
+  schema.attach<flight>("flight");
+  db.query(schema).create()
+  .table<airplane>("airplane")
+  .execute();
+
+  REQUIRE(db.exists("airplane"));
+
+  db.query(schema).create()
+  .table<flight>("flight")
+  .execute();
+
+  REQUIRE(db.exists("flight"));
+
+  db.query(schema).drop().table("flight").execute();
+  db.query(schema).drop().table("airplane").execute();
+
+  REQUIRE(!db.exists("flight"));
+  REQUIRE(!db.exists("airplane"));
+}
+
+TEST_CASE_METHOD(QueryFixture, "Execute select statement with where clause", "[session]")
+{
+  schema.attach<person>("person");
+  db.query(schema).create()
+  .table<person>("person")
+  .execute();
+
+  person george{7, "george", 45};
+  george.image.push_back(37);
+
+  auto res = db.query(schema)
+  .insert()
+  .into("person", column_generator::generate<person>(schema, true))
+  .values(george)
+  .execute();
+  REQUIRE(res == 1);
+
+  // fetch person as record
+  auto result_record = db.query(schema)
+    .select(column_generator::generate<person>(schema, true))
+    .from("person")
+    .where("id"_col == 7)
+    .fetch_all();
+
+  for (const auto &i: result_record) {
+    REQUIRE(i.size() == 4);
+    REQUIRE(i.at(0).name() == "id");
+    REQUIRE(i.at(0).is_integer());
+    REQUIRE(i.at(0).as<long long>() == george.id);
+    REQUIRE(i.at(1).name() == "name");
+    REQUIRE(i.at(1).is_varchar());
+    REQUIRE(i.at(1).as<std::string>() == george.name);
+    REQUIRE(i.at(2).name() == "age");
+    REQUIRE(i.at(2).is_integer());
+    REQUIRE(i.at(2).as<long long>() == george.age);
+  }
+
+  // fetch person as person
+  auto result_person = db.query(schema)
+    .select(column_generator::generate<person>(schema, true))
+    .from("person")
+    .where("id"_col == 7)
+    .fetch_all<person>();
+
+  for (const auto &i: result_person) {
+    REQUIRE(i.id == 7);
+    REQUIRE(i.name == "george");
+    REQUIRE(i.age == 45);
+  }
+
+  db.query(schema).drop().table("person").execute();
+}
+
+TEST_CASE_METHOD(QueryFixture, "Execute insert statement", "[session]")
+{
+  db.query(schema).create()
+  .table("person", {
+  make_pk_column<unsigned long>("id"),
+  make_column<std::string>("name", 255),
+  make_column<std::string>("color", 63)
+  })
+  .execute();
+
+  auto res = db.query(schema).insert()
+  .into("person", {{"", "id", ""}, {"", "name", ""}, {"", "color", ""}})
+  .values({7, "george", "green"})
+  .execute();
+
+  REQUIRE(res == 1);
+
+  // fetch person as record
+  auto result_record = db.query(schema).select({"id", "name", "color"})
+  .from("person")
+  .where("id"_col == 7)
+  .fetch_all();
+
+  for (const auto &i: result_record) {
+    REQUIRE(i.size() == 3);
+    REQUIRE(i.at(0).name() == "id");
+    REQUIRE(i.at(0).is_integer());
+    REQUIRE(i.at(0).as<unsigned long>() == 7);
+    REQUIRE(i.at(1).name() == "name");
+    REQUIRE(i.at(1).is_varchar());
+    REQUIRE(i.at(1).as<std::string>() == "george");
+    REQUIRE(i.at(2).name() == "color");
+    REQUIRE(i.at(2).is_varchar());
+    REQUIRE(i.at(2).as<std::string>() == "green");
+  }
+
+  db.query(schema).drop().table("person").execute();
+}
+
+TEST_CASE_METHOD(QueryFixture, "Select statement with foreign key", "[session]")
+{
+  schema.attach<airplane>("airplane");
+  schema.attach<flight>("flight");
+  db.query(schema).create()
+  .table<airplane>("airplane")
+  .execute();
+
+  db.query(schema).create()
+  .table<flight>("flight")
+  .execute();
+
+  std::vector<entity<airplane>> planes{
+  make_entity<airplane>(1, "Airbus", "A380"),
+  make_entity<airplane>(2, "Boeing", "707"),
+  make_entity<airplane>(3, "Boeing", "747")
+  };
+
+  for (const auto &plane: planes) {
+    auto res = db.query(schema)
+      .insert()
+      .into("airplane", column_generator::generate<airplane>(schema, true))
+      .values(*plane)
+      .execute();
+    REQUIRE(res == 1);
+  }
+
+  auto count = db.query(schema)
+    .select({count_all()})
+    .from("airplane")
+    .fetch_value<int>().value();
+  REQUIRE(count == 3);
+
+  flight f4711{4, planes.at(1), "hans"};
+
+  auto res = db.query(schema)
+    .insert()
+    .into("flight", column_generator::generate<flight>(schema, true))
+    .values(f4711)
+    .execute();
+  REQUIRE(res == 1);
+
+  auto f = *db.query(schema)
+    .select(column_generator::generate<flight>(schema, true))
+    .from("flight")
+    .fetch_all().begin();
+  REQUIRE(f.at(0).as<unsigned long>() == 4);
+  REQUIRE(f.at(1).as<unsigned long>() == 2);
+  REQUIRE(f.at(2).as<std::string>() == "hans");
+
+  db.query(schema).drop().table("flight").execute();
+  db.query(schema).drop().table("airplane").execute();
+}
+
+TEST_CASE_METHOD(QueryFixture, "Select statement with foreign key and join_left", "[session][join_left]")
+{
+  schema.attach<airplane>("airplane");
+  schema.attach<flight>("flight");
+  db.query(schema).create()
+  .table<airplane>("airplane")
+  .execute();
+
+  db.query(schema).create()
+  .table<flight>("flight")
+  .execute();
+
+  std::vector<entity<airplane>> planes{
+  make_entity<airplane>(1, "Airbus", "A380"),
+  make_entity<airplane>(2, "Boeing", "707"),
+  make_entity<airplane>(3, "Boeing", "747")
+  };
+
+  for (const auto &plane: planes) {
+    auto res = db.query(schema)
+      .insert()
+      .into("airplane", column_generator::generate<airplane>(schema, true))
+      .values(*plane)
+      .execute();
+    REQUIRE(res == 1);
+  }
+
+  auto count = db.query(schema)
+    .select({count_all()})
+    .from("airplane")
+    .fetch_value<int>().value();
+  REQUIRE(count == 3);
+
+  std::vector<entity<flight>> flights{
+  make_entity<flight>(4, planes.at(0), "hans"),
+  make_entity<flight>(5, planes.at(0), "otto"),
+  make_entity<flight>(6, planes.at(1), "george"),
+  make_entity<flight>(7, planes.at(2), "paul")
+  };
+
+  for (const auto &f: flights) {
+    auto res = db.query(schema)
+      .insert()
+      .into("flight", {"id", "airplane_id", "pilot_name"})
+      .values(*f)
+      .execute();
+    REQUIRE(res == 1);
+  }
+
+  auto f = *db.query(schema)
+    .select(column_generator::generate<flight>(schema, true))
+    .from("flight")
+    .fetch_all().begin();
+  REQUIRE(f.at(0).as<unsigned long>() == 4);
+  REQUIRE(f.at(1).as<unsigned long>() == 1);
+  REQUIRE(f.at(2).as<std::string>() == "hans");
+
+  auto result = db.query(schema).select({"f.id", "ap.brand", "ap.model", "f.pilot_name"})
+    .from({"flight", "f"})
+    .join_left({"airplane", "ap"})
+    .on("f.airplane_id"_col == "ap.id"_col)
+    .order_by("f.id").asc()
+    .fetch_all();
+
+  std::vector<std::pair<unsigned long, std::string>> expected_result {
+    {4, "hans"},
+    {5, "otto"},
+    {6, "george"},
+    {7, "paul"}
+  };
+  size_t index{0};
+  for (const auto &r: result) {
+    REQUIRE(r.size() == 4);
+    REQUIRE(r.at(0).as<unsigned long>() == expected_result[index].first);
+    REQUIRE(r.at(3).as<std::string>() == expected_result[index++].second);
+  }
+
+  db.query(schema).drop().table("flight").execute();
+  db.query(schema).drop().table("airplane").execute();
+}
+
+TEST_CASE_METHOD(QueryFixture, "Select statement with foreign key and for single entity", "[session][join_left][find]") {
+  schema.attach<airplane>("airplane");
+  schema.attach<flight>("flight");
+  db.query(schema).create()
+  .table<airplane>("airplane")
+  .execute();
+
+  db.query(schema).create()
+  .table<flight>("flight")
+  .execute();
+
+  std::vector<entity<airplane>> planes{
+  make_entity<airplane>(1, "Airbus", "A380"),
+  make_entity<airplane>(2, "Boeing", "707"),
+  make_entity<airplane>(3, "Boeing", "747")
+  };
+
+  for (const auto &plane: planes) {
+    auto res = db
+      .query(schema)
+      .insert()
+      .into("airplane", column_generator::generate<airplane>(schema, true))
+      .values(*plane)
+      .execute();
+    REQUIRE(res == 1);
+  }
+
+  auto count = db
+    .query(schema)
+    .select({count_all()})
+    .from("airplane")
+    .fetch_value<int>().value();
+  REQUIRE(count == 3);
+
+  std::vector<entity<flight>> flights{
+  make_entity<flight>(4, planes.at(0), "hans"),
+  make_entity<flight>(5, planes.at(0), "otto"),
+  make_entity<flight>(6, planes.at(1), "george"),
+  make_entity<flight>(7, planes.at(2), "paul")
+  };
+
+  for (const auto &f: flights) {
+    auto res = db.query(schema)
+      .insert()
+      .into("flight", column_generator::generate<flight>(schema, true))
+      .values(*f)
+      .execute();
+    REQUIRE(res == 1);
+  }
+
+  auto f = db.query(schema)
+    .select(column_generator::generate<flight>(schema, true))
+    .from("flight")
+    .fetch_one();
+  REQUIRE(f.has_value());
+  REQUIRE(f->at(0).as<unsigned long>() == 4);
+  REQUIRE(f->at(1).as<unsigned long>() == 1);
+  REQUIRE(f->at(2).as<std::string>() == "hans");
+
+  auto result = db
+    .query(schema)
+    .select({"f.id", "f.airplane_id", "ap.brand", "ap.model", "f.pilot_name"})
+    .from({"flight", "f"})
+    .join_left({"airplane", "ap"})
+    .on("f.airplane_id"_col == "ap.id"_col)
+    .where("f.id"_col == 4)
+    .fetch_one<flight>();
+
+  auto expected_flight = flights[0];
+
+  REQUIRE(result);
+  REQUIRE(result->id == expected_flight->id);
+  REQUIRE(result->pilot_name == expected_flight->pilot_name);
+  REQUIRE(result->airplane.get());
+  REQUIRE(result->airplane->id == 1);
+  REQUIRE(result->airplane->model == "A380");
+  REQUIRE(result->airplane->brand == "Airbus");
+
+  db.query(schema).drop().table("flight").execute();
+  db.query(schema).drop().table("airplane").execute();
+}
+
+TEST_CASE_METHOD(QueryFixture, "Select statement with many to many relationship", "[session][join][many_to_many]") {
+  schema.attach<recipe>("recipes");
+  schema.attach<ingredient>("ingredients");
+  schema.attach<recipe_ingredient>("recipe_ingredients");
+  db.query(schema).create()
+  .table<recipe>("recipes")
+  .execute();
+
+  db.query(schema).create()
+  .table<ingredient>("ingredients")
+  .execute();
+
+  db.query(schema).create()
+  .table<recipe_ingredient>("recipe_ingredients")
+  .execute();
+
+  std::vector<ingredient> ingredients {
+    {1, "Apple"},
+    {2, "Strawberry"},
+    {3, "Pineapple"},
+    {4, "Sugar"},
+    {5, "Flour"},
+    {6, "Butter"},
+    {7, "Beans"}
+  };
+
+  for (const auto &i: ingredients) {
+    auto res = db
+    .query(schema)
+    .insert()
+    .into("ingredients", column_generator::generate<ingredient>(schema, true))
+    .values(i)
+    .execute();
+    REQUIRE(res == 1);
+  }
+
+  std::vector<recipe> recipes{
+    {7, "Apple Crumble"},
+    {8, "Beans Chili"},
+    {9, "Fruit Salad"}
+  };
+
+  for (const auto &r: recipes) {
+    auto res = db
+    .query(schema)
+    .insert()
+    .into("recipes", column_generator::generate<recipe>(schema, true))
+    .values(r)
+    .execute();
+    REQUIRE(res == 1);
+  }
+
+  std::vector<std::pair<int, int>> recipe_ingredients {
+    { 7, 1 },
+    { 7, 4 },
+    { 7, 5 },
+    { 8, 6 },
+    { 8, 7 },
+    { 9, 1 },
+    { 9, 2 },
+    { 9, 3 }
+  };
+
+  for (const auto &ri: recipe_ingredients) {
+    auto res = db
+    .query(schema)
+    .insert()
+    .into("recipe_ingredients", column_generator::generate<recipe_ingredient>(schema, true))
+    .values({ri.first, ri.second})
+    .execute();
+    REQUIRE(res == 1);
+  }
+
+  auto result = db
+    .query(schema)
+    .select({"r.id", "r.name", "ri.ingredient_id"})
+    .from({"recipes", "r"})
+    .join_left({"recipe_ingredients", "ri"})
+    .on("r.id"_col == "ri.recipe_id"_col)
+    .fetch_all();
+
+  std::vector<std::tuple<unsigned long, std::string, unsigned long>> expected_result_one_join {
+    {7, "Apple Crumble", 1},
+    {7, "Apple Crumble", 4},
+    {7, "Apple Crumble", 5},
+    {8, "Beans Chili", 6},
+    {8, "Beans Chili", 7},
+    {9, "Fruit Salad", 1},
+    {9, "Fruit Salad", 2},
+    {9, "Fruit Salad", 3}
+  };
+  size_t index{0};
+  for (const auto &r: result) {
+    REQUIRE(r.size() == 3);
+    REQUIRE(r.at(0).as<unsigned long>().value() == std::get<0>(expected_result_one_join[index]));
+    REQUIRE(r.at(1).as<std::string>().value() == std::get<1>(expected_result_one_join[index]));
+    REQUIRE(r.at(2).as<unsigned long>().value() == std::get<2>(expected_result_one_join[index]));
+    ++index;
+  }
+
+  result = db
+  .query(schema)
+  .select({"r.id", "r.name", "ri.ingredient_id", "i.name"})
+  .from({"recipes", "r"})
+  .join_left({"recipe_ingredients", "ri"}).on("r.id"_col == "ri.recipe_id"_col)
+  .join_left({"ingredients", "i"}).on("ri.ingredient_id"_col == "i.id"_col)
+  .fetch_all();
+
+  std::vector<std::tuple<unsigned long, std::string, unsigned long, std::string>> expected_result_two_joins {
+    {7, "Apple Crumble", 1, "Apple"},
+    {7, "Apple Crumble", 4, "Sugar"},
+    {7, "Apple Crumble", 5, "Flour"},
+    {8, "Beans Chili", 6, "Butter"},
+    {8, "Beans Chili", 7, "Beans"},
+    {9, "Fruit Salad", 1, "Apple"},
+    {9, "Fruit Salad", 2, "Strawberry"},
+    {9, "Fruit Salad", 3, "Pineapple"}
+  };
+  index = 0;
+  for (const auto &r: result) {
+    REQUIRE(r.size() == 4);
+    REQUIRE(r.at(0).as<unsigned long>().value() == std::get<0>(expected_result_two_joins[index]));
+    REQUIRE(r.at(1).as<std::string>().value() == std::get<1>(expected_result_two_joins[index]));
+    REQUIRE(r.at(2).as<unsigned long>().value() == std::get<2>(expected_result_two_joins[index]));
+    REQUIRE(r.at(3).as<std::string>().value() == std::get<3>(expected_result_two_joins[index]));
+    ++index;
+  }
+
+  result = db
+  .query(schema)
+  .select({"r.id", "r.name", "ri.ingredient_id", "i.name"})
+  .from({"recipes", "r"})
+  .join_left({"recipe_ingredients", "ri"}).on("r.id"_col == "ri.recipe_id"_col)
+  .join_left({"ingredients", "i"}).on("ri.ingredient_id"_col == "i.id"_col)
+  .where("r.id"_col == 8)
+  .fetch_all();
+
+  index = 3;
+  for (const auto &r: result) {
+    REQUIRE(r.size() == 4);
+    REQUIRE(r.at(0).as<unsigned long>().value() == std::get<0>(expected_result_two_joins[index]));
+    REQUIRE(r.at(1).as<std::string>().value() == std::get<1>(expected_result_two_joins[index]));
+    REQUIRE(r.at(2).as<unsigned long>().value() == std::get<2>(expected_result_two_joins[index]));
+    REQUIRE(r.at(3).as<std::string>().value() == std::get<3>(expected_result_two_joins[index]));
+    ++index;
+  }
+
+  db.query(schema).drop().table("recipe_ingredients").execute();
+  db.query(schema).drop().table("recipes").execute();
+  db.query(schema).drop().table("ingredients").execute();
+}

backends/tests/SessionTest.cpp

@@ -0,0 +1,99 @@
+#include "catch2/catch_test_macros.hpp"
+
+#include "connection.hpp"
+
+#include "matador/sql/session.hpp"
+
+#include "models/airplane.hpp"
+#include "models/flight.hpp"
+
+class SessionFixture
+{
+public:
+  SessionFixture()
+    : pool(matador::test::connection::dns, 4)
+    , ses(pool)
+  {}
+
+  ~SessionFixture()
+  {
+    drop_table_if_exists("flights");
+    drop_table_if_exists("airplanes");
+  }
+
+protected:
+  matador::sql::connection_pool<matador::sql::connection> pool;
+  matador::sql::session ses;
+
+private:
+  void drop_table_if_exists(const std::string &table_name)
+  {
+    if (ses.table_exists(table_name)) {
+      ses.drop_table(table_name);
+    }
+  }
+};
+
+using namespace matador;
+
+TEST_CASE_METHOD(SessionFixture, "Session relation test", "[session][relation]") {
+  using namespace matador;
+  ses.attach<test::airplane>("airplanes");
+  ses.attach<test::flight>("flights");
+  ses.create_schema();
+  auto plane = ses.insert<test::airplane>(1, "Boeing", "A380");
+  auto f = ses.insert<test::flight>(2, plane, "sully");
+
+  auto result = ses.find<test::flight>(2);
+  REQUIRE(result.is_ok());
+}
+
+TEST_CASE_METHOD(SessionFixture, "Use session to find object with id", "[session][find]") {
+  using namespace matador::test;
+  ses.attach<airplane>("airplanes");
+  ses.create_schema();
+  auto a380 = ses.insert<airplane>(1, "Boeing", "A380");
+
+  auto result = ses.find<airplane>(2);
+  REQUIRE(!result.is_ok());
+  REQUIRE((result.err() == sql::session_error::FailedToFindObject));
+
+  result = ses.find<airplane>(1);
+
+  REQUIRE(result);
+  auto read_a380 = result.value();
+  REQUIRE(a380->id == read_a380->id);
+}
+
+TEST_CASE_METHOD(SessionFixture, "Use session to find all objects", "[session][find]") {
+  using namespace matador::test;
+  ses.attach<airplane>("airplanes");
+  ses.create_schema();
+
+  std::vector<std::unique_ptr<airplane>> planes;
+  planes.emplace_back(new airplane(1, "Airbus", "A380"));
+  planes.emplace_back(new airplane(2, "Boeing", "707"));
+  planes.emplace_back(new airplane(3, "Boeing", "747"));
+
+  for (auto &&plane: planes) {
+    ses.insert(plane.release());
+  }
+
+  auto result = ses.find<airplane>();
+
+  std::vector<std::tuple<int, std::string, std::string>> expected_result {
+    {1, "Airbus", "A380"},
+    {2, "Boeing", "707"},
+    {3, "Boeing", "747"}
+  };
+  REQUIRE(result);
+  auto all_planes = result.release();
+  size_t index {0};
+  for (const auto &i: all_planes) {
+    REQUIRE(i.id == std::get<0>(expected_result[index]));
+    REQUIRE(i.brand == std::get<1>(expected_result[index]));
+    REQUIRE(i.model == std::get<2>(expected_result[index]));
+    ++index;
+  }
+
+}

backends/tests/StatementCacheTest.cpp

@@ -5,18 +5,28 @@
 #include "matador/sql/session.hpp"
 #include "matador/sql/statement_cache.hpp"
 
+#include "connection.hpp"
+
 using namespace matador;
 
-TEST_CASE("Acquire prepared statement", "[statement cache]") {
+class StatementCacheFixture
+{
+public:
+  StatementCacheFixture()
+  : pool(matador::test::connection::dns, 4), ses(pool)
+  {}
+  ~StatementCacheFixture() = default;
+
+protected:
+  matador::sql::connection_pool<matador::sql::connection> pool;
+  matador::sql::session ses;
+};
+
+TEST_CASE_METHOD(StatementCacheFixture, "Acquire prepared statement", "[statement cache]") {
   sql::statement_cache cache;
-  sql::connection_pool<sql::connection> pool("sqlite://sqlite.db", 4);
 
-  sql::session s(pool);
   auto conn = pool.acquire();
 
   std::string sql = R"(SELECT * FROM person WHERE name = 'george')";
 //  auto &stmt = cache.acquire(sql, *conn);
-
-
-
 }

backends/tests/StatementTest.cpp

@@ -0,0 +1,117 @@
+#include <catch2/catch_test_macros.hpp>
+
+#include "matador/sql/column_definition.hpp"
+#include "matador/sql/condition.hpp"
+#include "matador/sql/connection.hpp"
+
+#include "connection.hpp"
+
+#include "models/airplane.hpp"
+
+using namespace matador::sql;
+using namespace matador::test;
+
+class StatementTestFixture
+{
+public:
+  StatementTestFixture()
+  : db(matador::test::connection::dns)
+  , schema(db.dialect().default_schema_name())
+  {
+    db.open();
+    db.query(schema).create().table<airplane>("airplane").execute();
+  }
+
+  ~StatementTestFixture()
+  {
+    drop_table_if_exists("airplane");
+  }
+
+protected:
+  matador::sql::connection db;
+  matador::sql::schema schema;
+
+  std::vector<entity<airplane>> planes{
+    make_entity<airplane>(1, "Airbus", "A380"),
+    make_entity<airplane>(2, "Boeing", "707"),
+    make_entity<airplane>(3, "Boeing", "747")
+  };
+
+private:
+  void drop_table_if_exists(const std::string &table_name) {
+    if (db.exists(table_name)) {
+      db.query(schema).drop().table(table_name).execute();
+    }
+  }
+
+};
+
+TEST_CASE_METHOD(StatementTestFixture, "Create prepared statement", "[statement]")
+{
+  schema.attach<airplane>("airplane");
+  table ap{"airplane"};
+  SECTION("Insert with prepared statement and placeholder") {
+    auto stmt = db.query(schema).insert()
+    .into("airplane", column_generator::generate<airplane>(schema, true))
+    .values<airplane>()
+    .prepare();
+
+    for (const auto &plane: planes) {
+      auto res = stmt.bind(*plane).execute();
+      REQUIRE(res == 1);
+      stmt.reset();
+    }
+
+    auto result = db.query(schema)
+      .select(column_generator::generate<airplane>(schema, true))
+      .from(ap)
+      .fetch_all<airplane>();
+
+    size_t index{0};
+    for (const auto &i: result) {
+      REQUIRE(i.id == planes[index]->id);
+      REQUIRE(i.brand == planes[index]->brand);
+      REQUIRE(i.model == planes[index++]->model);
+    }
+  }
+
+  SECTION("Select with prepared statement") {
+    for (const auto &plane: planes) {
+      auto res = db.query(schema)
+        .insert()
+        .into("airplane", column_generator::generate<airplane>(schema, true))
+        .values(*plane)
+        .execute();
+      REQUIRE(res == 1);
+    }
+
+    auto stmt = db.query(schema)
+      .select(column_generator::generate<airplane>(schema, true))
+      .from(ap)
+      .where("brand"_col == _)
+      .prepare();
+
+    stmt.bind(0, "Airbus");
+
+    auto result = stmt.fetch<airplane>();
+
+    for (const auto &i: result) {
+      REQUIRE(i.id == planes[0]->id);
+      REQUIRE(i.brand == planes[0]->brand);
+      REQUIRE(i.model == planes[0]->model);
+    }
+
+    stmt.reset();
+
+    stmt.bind(0, "Boeing");
+
+    result = stmt.fetch<airplane>();
+
+    size_t index{1};
+    for (const auto &i: result) {
+      REQUIRE(i.id == planes[index]->id);
+      REQUIRE(i.brand == planes[index]->brand);
+      REQUIRE(i.model == planes[index++]->model);
+    }
+  }
+}

backends/tests/TypeTraitsTest.cpp

@@ -0,0 +1,131 @@
+#include <catch2/catch_test_macros.hpp>
+
+#include "matador/sql/connection.hpp"
+#include "matador/sql/column_generator.hpp"
+
+#include "matador/utils/enum_mapper.hpp"
+
+#include "connection.hpp"
+
+#include "models/location.hpp"
+
+using namespace matador::sql;
+using namespace matador::test;
+
+class TypeTraitsTestFixture
+{
+public:
+  TypeTraitsTestFixture()
+  : db(matador::test::connection::dns)
+  , schema(db.dialect().default_schema_name())
+  {
+    db.open();
+    db.query(schema).create()
+    .table<location>("location")
+    .execute();
+  }
+
+  ~TypeTraitsTestFixture()
+  {
+    db.query(schema).drop().table("location").execute();
+  }
+
+protected:
+  matador::sql::connection db;
+  matador::sql::schema schema;
+
+private:
+  void drop_table_if_exists(const std::string &table_name) {
+    if (db.exists(table_name)) {
+      db.query(schema).drop().table(table_name).execute();
+    }
+  }
+};
+
+static const matador::utils::enum_mapper<Color> color_enum({
+                                                           {Color::Green,  "green"},
+                                                           {Color::Red,    "red"},
+                                                           {Color::Blue,   "blue"},
+                                                           {Color::Yellow, "yellow"},
+                                                           {Color::Black,  "black"},
+                                                           {Color::White,  "white"},
+                                                           {Color::Brown,  "brown"}
+                                                           });
+
+template<>
+struct matador::sql::data_type_traits<Color, void>
+{
+    inline static data_type_t builtin_type(std::size_t size)
+    { return data_type_traits<std::string>::builtin_type(size); }
+
+    static void read_value(query_result_reader &reader, const char *id, size_t index, Color &value)
+    {
+        std::string enum_string;
+        reader.read_value(id, index, enum_string, 64);
+        if (const auto enum_opt = color_enum.to_enum(enum_string)) {
+            value = enum_opt.value();
+        }
+    }
+
+    static any_type create_value(const Color &value)
+    {
+        return color_enum.to_string(value);
+    }
+
+    static void bind_value(parameter_binder &binder, size_t index, Color &value)
+    {
+        binder.bind(index, color_enum.to_string(value));
+    }
+};
+
+TEST_CASE_METHOD(TypeTraitsTestFixture, "Special handling of attributes with type traits", "[typetraits]")
+{
+  schema.attach<location>("location");
+  SECTION("Insert and select with direct execution") {
+    location loc{1, "center", {1, 2, 3}, Color::Black};
+
+    auto res = db
+      .query(schema)
+      .insert()
+      .into("location", column_generator::generate<location>(schema, true))
+      .values(loc)
+      .execute();
+    REQUIRE(res == 1);
+
+    auto result = db
+      .query(schema)
+      .select(column_generator::generate<location>(schema, true))
+      .from("location")
+      .fetch_all<location>();
+
+    for (const auto &l: result) {
+      REQUIRE(l.name == "center");
+    }
+  }
+
+  SECTION("Insert and select with prepared statement") {
+    location loc{1, "center", {1, 2, 3}, Color::Black};
+
+    auto stmt = db
+      .query(schema)
+      .insert()
+      .into("location", column_generator::generate<location>(schema, true))
+      .values<location>()
+      .prepare();
+
+    auto res = stmt
+      .bind(loc)
+      .execute();
+    REQUIRE(res == 1);
+
+    auto result = db
+      .query(schema)
+      .select(column_generator::generate<location>(schema, true))
+      .from("location")
+      .fetch_all<location>();
+
+    for (const auto &l: result) {
+      REQUIRE(l.name == "center");
+    }
+  }
+}

demo/author.json

@@ -0,0 +1,27 @@
+{
+  "name": "book",
+  "fields": {
+    "id": {
+      "type": "unsigned long",
+      "constraint": "primary_key"
+    },
+    "first_name": {
+      "type": "string",
+      "size": 63
+    },
+    "last_name": {
+      "type": "string",
+      "size": 63
+    },
+    "date_of_birth": {
+      "type": "string",
+      "size": 31
+    },
+    "year_of_birth": {
+      "type": "unsigned short"
+    },
+    "distinguished": {
+      "type": "boolean"
+    }
+  }
+}

demo/book.json

@@ -0,0 +1,23 @@
+{
+  "name": "book",
+  "fields": {
+    "id": {
+      "type": "unsigned long",
+      "constraint": "primary_key"
+    },
+    "title": {
+      "type": "string",
+      "size": 511
+    },
+    "book_author": {
+      "type": "author",
+      "constraint": {
+        "type": "foreign_key",
+        "references": "id"
+      }
+    },
+    "published_in": {
+      "type": "unsigned_short"
+    }
+  }
+}

demo/main.cpp

@@ -1,17 +1,295 @@
-#include <cstdlib>
+#include "matador/sql/column.hpp"
+#include "matador/sql/condition.hpp"
+#include "matador/sql/schema.hpp"
+#include "matador/sql/connection.hpp"
+#include "matador/sql/entity.hpp"
+
+#include "matador/utils/access.hpp"
+#include "matador/utils/enum_mapper.hpp"
+
+#include "matador/sql/query_helper.hpp"
+
 #include <iostream>
 #include <string>
 
+struct author {
+    unsigned long id{};
+    std::string first_name;
+    std::string last_name;
+    std::string date_of_birth;
+    unsigned short year_of_birth{};
+    bool distinguished{false};
+
+    template<typename Operator>
+    void process( Operator& op ) {
+        namespace field = matador::utils::access;
+        field::primary_key( op, "id", id );
+        field::attribute( op, "first_name", first_name, 63 );
+        field::attribute( op, "last_name", last_name, 63 );
+        field::attribute( op, "date_of_birth", date_of_birth, 31 );
+        field::attribute( op, "year_of_birth", year_of_birth );
+        field::attribute( op, "distinguished", distinguished );
+    }
+};
+
+struct book {
+    unsigned long id{};
+    matador::sql::entity<author> book_author;
+    std::string title;
+    unsigned short published_in{};
+
+    template<typename Operator>
+    void process( Operator& op ) {
+        namespace field = matador::utils::access;
+        field::primary_key( op, "id", id );
+        field::attribute( op, "title", title, 511 );
+        field::has_one( op, "author_id", book_author, matador::utils::default_foreign_attributes );
+        field::attribute( op, "published_in", published_in );
+    }
+};
+
+struct payload {
+    unsigned long id{};
+
+    template<typename Operator>
+    void process( Operator& op ) {
+        namespace field = matador::utils::access;
+        field::primary_key( op, "id", id );
+    }
+};
+
+struct job {
+    enum class job_state {
+        Pending,
+        Running,
+        Succeeded,
+        Failed,
+        Canceled
+    };
+
+    enum class job_mode {
+        Foreground,
+        Background
+    };
+
+    unsigned long id{};
+    matador::sql::entity<payload> payload;
+    std::string type;
+    std::string description;
+    job_state state;
+    job_mode mode;
+
+    template<typename Operator>
+    void process( Operator& op ) {
+        namespace field = matador::utils::access;
+        field::primary_key( op, "id", id );
+        field::belongs_to( op, "payload", payload, matador::utils::default_foreign_attributes );
+        field::attribute( op, "type", type, 511 );
+        field::attribute( op, "description", description, 511 );
+        field::attribute( op, "state", state );
+        field::attribute( op, "mode", mode );
+    }
+};
+
+static const matador::utils::enum_mapper<job::job_state> job_state_enum({
+                                                           {job::job_state::Pending,  "Pending"},
+                                                           {job::job_state::Running,  "Running"},
+                                                           {job::job_state::Succeeded,  "Succeeded"},
+                                                           {job::job_state::Failed,  "Failed"},
+                                                           {job::job_state::Canceled,  "Canceled"}
+                                                           });
+
+static const matador::utils::enum_mapper<job::job_mode> job_mode_enum({
+                                                           {job::job_mode::Foreground,  "Foreground"},
+                                                           {job::job_mode::Background,  "Background"}
+                                                           });
+
+template<>
+struct matador::sql::data_type_traits<job::job_state, void>
+{
+    inline static data_type_t builtin_type(std::size_t size)
+    { return data_type_traits<std::string>::builtin_type(size); }
+
+    static void read_value(query_result_reader &reader, const char *id, size_t index, job::job_state &value)
+    {
+        std::string enum_string;
+        reader.read_value(id, index, enum_string, 64);
+        if (const auto enum_opt = job_state_enum.to_enum(enum_string)) {
+            value = enum_opt.value();
+        }
+    }
+
+    static any_type create_value(const job::job_state &value)
+    {
+        return job_state_enum.to_string(value);
+    }
+
+    static void bind_value(parameter_binder &binder, size_t index, job::job_state &value)
+    {
+        binder.bind(index, job_state_enum.to_string(value));
+    }
+};
+
+template<>
+struct matador::sql::data_type_traits<job::job_mode, void>
+{
+    inline static data_type_t builtin_type(std::size_t size)
+    { return data_type_traits<std::string>::builtin_type(size); }
+
+    static void read_value(query_result_reader &reader, const char *id, size_t index, job::job_mode &value)
+    {
+        std::string enum_string;
+        reader.read_value(id, index, enum_string, 64);
+        if (const auto enum_opt = job_mode_enum.to_enum(enum_string)) {
+            value = enum_opt.value();
+        }
+    }
+
+    static any_type create_value(const job::job_mode &value)
+    {
+        return job_mode_enum.to_string(value);
+    }
+
+    static void bind_value(parameter_binder &binder, size_t index, job::job_mode &value)
+    {
+        binder.bind(index, job_mode_enum.to_string(value));
+    }
+};
+
+QUERY_HELPER( authors, id, first_name, last_name, date_of_birth, year_of_birth, distinguished )
+
+QUERY_HELPER( books, id, author_id, title, published_in )
+
+QUERY_HELPER( job, id, payload, type, description, state, mode )
+
+QUERY_HELPER( payload, id )
+
+QUERY_HELPER( temporary_table, id );
+
 int main() {
+    using namespace matador::sql;
+    using namespace matador;
+
     const std::string env_var{"MATADOR_BACKENDS_PATH"};
 
-//  char var[1024];
+    std::string dns{"sqlite://demo.db"};
-//  size_t len{};
+    schema s( "main" );
-//  const auto error = getenv_s(&len, var, 1024, env_var.c_str());
+    s.attach<author>( "authors" );
-//  if (error > 0) {
+    s.attach<book>( "books" );
-//    std::cout << "error: unknown env var " << env_var << "\n";
+
-//  } else {
+    connection c( dns );
-//    std::cout << "env var: " << var << "\n";
+    c.open();
-//  }
+    s.create( c );
+
+    auto create_authors_sql = c.query( s )
+                               .create()
+                               .table<author>( qh::authors )
+                               .execute();
+
+    c.query( s )
+     .create()
+     .table<book>( qh::books )
+     .execute();
+
+    std::cout << "SQL: " << create_authors_sql << "\n";
+
+    author mc;
+    mc.id = 1;
+    mc.first_name = "Michael";
+    mc.last_name = "Crichton";
+    mc.date_of_birth = "19.8.1954";
+    mc.year_of_birth = 1954;
+    mc.distinguished = true;
+    auto insert_authors_sql = c.query( s )
+                               .insert()
+                               .into( qh::authors )
+                               .values( mc )
+                               .execute();
+
+    std::cout << "SQL: " << insert_authors_sql << "\n";
+
+    auto result = c.query( s )
+                   .select( qh::authors.columns )
+                   .from( qh::authors )
+                   .fetch_all();
+
+    for (const auto& row: result) { std::cout << "Author " << row.at( qh::authors.first_name ) << "\n"; }
+
+    auto update_authors_sql = c.query( s )
+                               .update( qh::authors )
+                               .set( {{qh::authors.first_name, "Stephen"},
+                                      {qh::authors.last_name, "King"}} )
+                               .where( qh::authors.last_name == "Crichton" )
+                               .execute();
+
+    std::cout << "SQL: " << update_authors_sql << "\n";
+
+    auto authors = c.query( s )
+                    .select( qh::authors.columns )
+                    .from( qh::authors )
+                    .fetch_all<author>();
+
+    for (const auto& a: authors) { std::cout << "Author " << a.first_name << "\n"; }
+
+    c.query( s )
+     .insert()
+     .into( qh::books )
+     .values( {2, "It", mc.id, 1980} )
+     .execute();
+
+    c.query( s )
+     .insert()
+     .into( qh::books )
+     .values( {3, "Misery", mc.id, 1984} )
+     .execute();
+
+    auto select_books_sql = c.query( s )
+                             .select( qh::books.columns, {qh::authors.last_name} )
+                             .from( qh::books )
+                             .join_left( qh::authors )
+                             .on( qh::books.author_id == qh::authors.id )
+                             .where( qh::books.published_in < 2008 && qh::authors.last_name == "King" )
+                             .group_by( qh::books.published_in )
+                             .order_by( qh::books.title ).asc()
+                             .limit( 5 )
+                             .offset( 2 )
+                             .fetch_all();
+
+    for (const auto& r: select_books_sql) { std::cout << "R: " << r.at( qh::books.title ) << ", " << r.at( qh::authors.last_name ) << "\n"; }
+    // SELECT book.title, book.id, book.author_id, book.published_in, author.name
+    // FROM book
+    // INNER JOIN author ON book.author_id = author.id
+    // WHERE book.published_in < 2008 AND author.name = "Michael Crichton"
+    // ORDER BY "book.title" ASC
+    // OFFSET 2 LIMIT 5
+
+    c.query( s ).drop().table( qh::books ).execute();
+
+    auto drop_authors_sql = c.query( s )
+                             .drop()
+                             .table( qh::authors )
+                             .execute();
+
+    std::cout << "SQL: " << drop_authors_sql << "\n";
+
+    auto res = c.query( s )
+                .select( {qh::payload.id} )
+                .from( qh::payload )
+                .join_left( qh::job )
+                .on( qh::job.payload == qh::payload.id )
+                .where(
+                        in( qh::payload.id, c.query( s )
+                                             .select( {qh::job.state} )
+                                             .from( qh::job )
+                                             .where( qh::job.state == job::job_state::Running )
+                                ) &&
+                        in( qh::payload.id, c.query( s )
+                                             .select( {qh::temporary_table.id} )
+                                             .from( qh::temporary_table ) )
+                        )
+                .build();
+    // .fetch_value<unsigned long>();
+    std::cout << "SQL: " << res.sql << "\n";
+
     return 0;
 }

include/matador/sql/any_type.hpp

@@ -3,11 +3,24 @@
 
 #include "matador/sql/placeholder.hpp"
 
+#include "matador/utils/types.hpp"
+
 #include <string>
 #include <variant>
 
 namespace matador::sql {
 
+using any_db_type = std::variant<
+  long long,
+  unsigned long long,
+  double,
+  bool,
+  const char*,
+  std::string,
+  utils::blob,
+  placeholder,
+  nullptr_t>;
+
 using any_type = std::variant<
   char, short, int, long, long long,
   unsigned char, unsigned short, unsigned int, unsigned long, unsigned long long,
@@ -15,6 +28,7 @@ using any_type = std::variant<
   bool,
   const char*,
   std::string,
+  utils::blob,
   placeholder,
   nullptr_t>;
 

include/matador/sql/any_type_to_string_visitor.hpp

@@ -0,0 +1,53 @@
+#ifndef QUERY_ANY_TYPE_TO_STRING_VISITOR_HPP
+#define QUERY_ANY_TYPE_TO_STRING_VISITOR_HPP
+
+#include "matador/utils/types.hpp"
+
+#include "matador/sql/placeholder.hpp"
+
+#include <string>
+
+namespace matador::sql {
+
+class dialect;
+class query_context;
+
+struct any_type_to_string_visitor
+{
+  explicit any_type_to_string_visitor(const dialect &d, query_context &query);
+
+  void operator()(char &x) { to_string(x); }
+  void operator()(short &x) { to_string(x); }
+  void operator()(int &x) { to_string(x); }
+  void operator()(long &x) { to_string(x); }
+  void operator()(long long &x) { to_string(x); }
+  void operator()(unsigned char &x) { to_string(x); }
+  void operator()(unsigned short &x) { to_string(x); }
+  void operator()(unsigned int &x) { to_string(x); }
+  void operator()(unsigned long &x) { to_string(x); }
+  void operator()(unsigned long long &x) { to_string(x); }
+  void operator()(bool &x) { to_string(x); }
+  void operator()(float &x) { to_string(x); }
+  void operator()(double &x) { to_string(x); }
+  void operator()(const char *x) { to_string(x); }
+  void operator()(std::string &x) { to_string(x); }
+  void operator()(utils::blob &x) { to_string(x); }
+  void operator()(placeholder &x) { to_string(x); }
+
+  template<typename Type>
+  void to_string(Type &val)
+  {
+    result = std::to_string(val);
+  }
+  void to_string(const char *val);
+  void to_string(std::string &val);
+  void to_string(utils::blob &val);
+  void to_string(placeholder &val);
+
+  const dialect &d;
+  query_context &query;
+  std::string result;
+};
+
+}
+#endif //QUERY_ANY_TYPE_TO_STRING_VISITOR_HPP

include/matador/sql/any_type_to_visitor.hpp

@@ -1,111 +1,14 @@
 #ifndef QUERY_ANY_TYPE_TO_VISITOR_HPP
 #define QUERY_ANY_TYPE_TO_VISITOR_HPP
 
-#include <array>
+#include "matador/sql/convert.hpp"
-#include <charconv>
+
-#include <cstring>
-#include <stdexcept>
 #include <string>
-#include <type_traits>
 
 namespace matador::sql {
 
 struct placeholder;
 
-template < typename DestType, typename SourceType >
-void convert(DestType &dest, SourceType source, typename std::enable_if<std::is_same<DestType, SourceType>::value>::type* = nullptr)
-{
-  dest = source;
-}
-
-template < typename DestType, typename SourceType >
-void convert(DestType &dest, SourceType source, typename std::enable_if<std::is_integral<DestType>::value && std::is_arithmetic<SourceType>::value && !std::is_same<DestType, SourceType>::value>::type* = nullptr)
-{
-  dest = static_cast<DestType>(source);
-}
-
-template < typename DestType, typename SourceType >
-void convert(DestType &dest, SourceType source, typename std::enable_if<std::is_floating_point<DestType>::value && std::is_arithmetic<SourceType>::value && !std::is_same<DestType, SourceType>::value>::type* = nullptr)
-{
-  dest = static_cast<DestType>(source);
-}
-
-void convert(std::string &dest, bool source);
-
-template < typename SourceType >
-void convert(std::string &dest, SourceType source, typename std::enable_if<std::is_integral<SourceType>::value && !std::is_same<bool, SourceType>::value>::type* = nullptr)
-{
-  std::array<char, 128> buffer{};
-  auto [ptr, ec] = std::to_chars(buffer.data(), buffer.data() + buffer.size(), source, 10);
-  if (ec == std::errc{}) {
-    dest.assign(buffer.data(), ptr);
-  } else {
-    throw std::logic_error("couldn't convert value to std::string");
-  }
-}
-
-template < typename SourceType >
-void convert(std::string &dest, SourceType source, typename std::enable_if<std::is_floating_point<SourceType>::value>::type* = nullptr)
-{
-  std::array<char, 128> buffer{};
-  auto [ptr, ec] = std::to_chars(buffer.data(), buffer.data() + buffer.size(), source);
-  if (ec == std::errc{}) {
-    dest.assign(buffer.data(), ptr);
-  } else {
-    throw std::logic_error("couldn't convert value to std::string");
-  }
-}
-
-void convert(std::string &dest, const char* source);
-
-unsigned long long to_unsigned_long_long(const char *source);
-
-template < typename DestType >
-void convert(DestType &dest, const std::string &source, typename std::enable_if<std::is_integral<DestType>::value && std::is_unsigned<DestType>::value>::type* = nullptr)
-{
-  dest = to_unsigned_long_long(source.c_str());
-}
-
-template < typename DestType >
-void convert(DestType &dest, const char *source, typename std::enable_if<std::is_integral<DestType>::value && std::is_unsigned<DestType>::value>::type* = nullptr)
-{
-  dest = to_unsigned_long_long(source);
-}
-
-long long to_long_long(const char *source);
-
-template < typename DestType >
-void convert(DestType &dest, const std::string &source, typename std::enable_if<std::is_integral<DestType>::value && std::is_signed<DestType>::value>::type* = nullptr)
-{
-  dest = to_long_long(source.c_str());
-}
-
-template < typename DestType >
-void convert(DestType &dest, const char *source, typename std::enable_if<std::is_integral<DestType>::value && std::is_signed<DestType>::value>::type* = nullptr)
-{
-  dest = to_long_long(source);
-}
-
-long double to_double(const char *source);
-
-template < typename DestType >
-void convert(DestType &dest, const std::string &source, typename std::enable_if<std::is_floating_point<DestType>::value>::type* = nullptr)
-{
-  dest = to_double(source.c_str());
-}
-
-template < typename DestType >
-void convert(DestType &dest, const char *source, typename std::enable_if<std::is_floating_point<DestType>::value>::type* = nullptr)
-{
-  dest = to_double(source);
-}
-
-template < typename DestType >
-void convert(DestType &dest, bool source, typename std::enable_if<std::is_floating_point<DestType>::value>::type* = nullptr)
-{
-  dest = static_cast<DestType>(source);
-}
-
 template < typename Type >
 struct any_type_to_visitor
 {
@@ -124,6 +27,7 @@ struct any_type_to_visitor
   void operator()(double &x) { convert(result, x); }
   void operator()(const char *x) { convert(result, x); }
   void operator()(std::string &x) { convert(result, x); }
+  void operator()(utils::blob &x) { convert(result, x); }
   void operator()(placeholder &/*x*/) {}
 
   Type result{};

include/matador/sql/backend_provider.hpp

@@ -6,6 +6,7 @@
 #include <memory>
 #include <string>
 #include <unordered_map>
+#include <unordered_set>
 
 namespace matador::sql {
 
@@ -26,28 +27,50 @@ public:
   const dialect& connection_dialect(const std::string &connection_type);
 
 private:
-  struct backend_context {
+  struct basic_backend_context {
-    backend_context(const std::string &connection_type,
+    virtual ~basic_backend_context() = default;
-                    const std::string &backends_path);
+    [[nodiscard]] virtual connection_impl* create(const connection_info&) = 0;
+    virtual void destroy(connection_impl*) = 0;
+    [[nodiscard]] virtual const sql::dialect* dialect() const = 0;
+  };
+
+  class backend_context final : public basic_backend_context {
+  public:
+    explicit backend_context(const std::string &connection_type);
     backend_context(const backend_context&) = delete;
     backend_context& operator=(const backend_context&) = delete;
     backend_context(backend_context&&) noexcept = default;
     backend_context& operator=(backend_context&&) noexcept = default;
-    ~backend_context();
+    ~backend_context() override;
 
+    [[nodiscard]] connection_impl* create(const connection_info&) override;
+    void destroy(connection_impl *conn) override;
+    [[nodiscard]] const class dialect* dialect() const override;
+
+  private:
     typedef connection_impl*(*create_func)(const connection_info&);
     typedef void (*destroy_func)(connection_impl*);
-    typedef const dialect*(*dialect_func)();
+    typedef const class dialect*(*dialect_func)();
 
     create_func create_connection{};
     destroy_func destroy_connection{};
     dialect_func get_dialect{};
     utils::library lib;
   };
+
+  class noop_backend_context final : public basic_backend_context {
+  public:
+    connection_impl *create(const connection_info &info) override;
+    void destroy(connection_impl *impl) override;
+    [[nodiscard]] const sql::dialect *dialect() const override;
+
   private:
-  using backends_t = std::unordered_map<std::string, std::unique_ptr<backend_context>>;
+    std::unordered_set<std::unique_ptr<connection_impl>> noop_connections_;
+  };
+
+private:
+  using backends_t = std::unordered_map<std::string, std::unique_ptr<basic_backend_context>>;
   backends_t backends_;
-  std::string backends_path_;
 };
 }
 #endif //QUERY_BACKEND_PROVIDER_HPP

include/matador/sql/basic_condition.hpp

@@ -33,7 +33,7 @@ public:
     LIKE
   };
 
-  virtual std::string evaluate(dialect &dialect, query_context &query) const = 0;
+  virtual std::string evaluate(const dialect &dialect, query_context &query) const = 0;
 
   static std::unordered_map<operand_t, std::string> operands;
 };

include/matador/sql/column.hpp

@@ -1,168 +1,43 @@
 #ifndef QUERY_COLUMN_HPP
 #define QUERY_COLUMN_HPP
 
-#include "matador/sql/any_type.hpp"
+#include <string>
-#include "matador/sql/any_type_to_visitor.hpp"
-#include "matador/sql/types.hpp"
-
-#include "matador/utils/field_attributes.hpp"
-
-#include <optional>
-#include <vector>
 
 namespace matador::sql {
 
-class column {
+struct table;
-public:
-  column(sql_function_t func, std::string name);
-  column(const char *name, std::string alias = ""); // NOLINT(*-explicit-constructor)
-  column(std::string name, std::string alias = ""); // NOLINT(*-explicit-constructor)
 
-  column(const column&) = default;
+enum class sql_function_t {
-  column& operator=(const column&) = default;
+  NONE,
-  column(column&&) noexcept = default;
+  COUNT,
-  column& operator=(column&&) noexcept = default;
+  AVG,
-
+  SUM,
-  template<typename Type>
+  MIN,
-  explicit column(std::string name, utils::field_attributes attr = utils::null_attributes)
+  MAX
-  : column(std::move(name), data_type_traits<Type>::builtin_type(attr.size()), attr)
+};
-  {}
+
-
+struct column
-  template<typename Type>
-  column(std::string name, const Type &, utils::field_attributes attr = utils::null_attributes)
-  : column(std::move(name), data_type_traits<Type>::builtin_type(attr.size()), attr)
-  {}
-
-  column(std::string name, data_type_t type, utils::field_attributes attr = utils::null_attributes);
-  template<typename Type>
-
-  column(std::string name, std::string ref_table, std::string ref_column, utils::field_attributes attr = utils::null_attributes)
-  : column(std::move(name), data_type_traits<Type>::builtin_type(attr.size()), ref_table, ref_column, attr)
-  {}
-
-  column(std::string name, data_type_t type, size_t index, std::string ref_table, std::string ref_column, utils::field_attributes attr = utils::null_attributes);
-
-  [[nodiscard]] const std::string& name() const;
-  [[nodiscard]] size_t index() const;
-  [[nodiscard]] const utils::field_attributes& attributes() const;
-  [[nodiscard]] data_type_t type() const;
-  [[nodiscard]] const std::string& alias() const;
-  [[nodiscard]] const std::string& ref_table() const;
-  [[nodiscard]] const std::string& ref_column() const;
-
-  void type(data_type_t type);
-  void alias(const std::string &as);
-
-  template< typename Type >
-  [[nodiscard]] bool is_type_of() const {
-    return std::holds_alternative<Type>(value_);
-  }
-
-  [[nodiscard]] std::string str() const;
-
-  template<typename Type>
-  void set(const Type &value, const utils::field_attributes &attr = utils::null_attributes)
 {
-    type_ = data_type_traits<Type>::builtin_type(attr.size());
+  column(const char *name); // NOLINT(*-explicit-constructor)
-    attributes_ = attr;
+  column(std::string name); // NOLINT(*-explicit-constructor)
-    value_ = value;
+  column(sql_function_t func, std::string name); // NOLINT(*-explicit-constructor)
-  }
+  column(std::string table_name, std::string name, std::string as = "");
+  column(std::string table_name, const char* name, std::string as = "");
+  column(struct table &t, const char* name, std::string as = "");
 
-  void set(const std::string &value, const utils::field_attributes &attr)
+  [[nodiscard]] bool equals(const column &x) const;
-  {
-    type_ = data_type_traits<std::string>::builtin_type(attr.size());
-    attributes_ = attr;
-    value_ = value;
-  }
 
-  void set(const char *value, const utils::field_attributes &attr)
+  column& as(std::string a);
-  {
-    type_ = data_type_traits<std::string>::builtin_type(attr.size());
-    attributes_ = attr;
-    value_ = value;
-  }
 
-  template<class Type>
-  Type as() const
-  {
-    const Type* ptr= std::get_if<Type>(&value_);
-    if (ptr) {
-      return *ptr;
-    }
-    any_type_to_visitor<Type> visitor;
-    std::visit(visitor, const_cast<any_type&>(value_));
-    return visitor.result;
-  }
-
   [[nodiscard]] bool is_function() const;
-  [[nodiscard]] sql_function_t function() const;
-
-private:
-  template<class Operator>
-  void process(Operator &op)
-  {
-    op.on_attribute(name_.c_str(), value_, type_, attributes_);
-  }
-
-  using data_type_index = std::vector<data_type_t>;
-
-private:
-  friend class record;
-
-  static const data_type_index data_type_index_;
 
-  std::string name_;
+  std::string table;
-  size_t index_{};
+  std::string name;
-  utils::field_attributes attributes_;
+  std::string alias;
-  data_type_t type_{data_type_t::type_unknown};
-  any_type value_;
   sql_function_t function_{sql_function_t::NONE};
-  std::string alias_;
-  std::string ref_table_;
-  std::string ref_column_;
 };
 
-/**
- * User defined literal to have a shortcut creating a column object
- * @param name Name of the column
- * @param len Length of the column name
- * @return A column object with given name
- */
 column operator "" _col(const char *name, size_t len);
 
-column make_column(const std::string &name, data_type_t type, utils::field_attributes attr = utils::null_attributes);
-
-template < typename Type >
-column make_column(const std::string &name, utils::field_attributes attr = utils::null_attributes)
-{
-    return make_column(name, data_type_traits<Type>::builtin_type(0), attr);
-}
-template <>
-column make_column<std::string>(const std::string &name, utils::field_attributes attr);
-
-template < typename Type >
-column make_pk_column(const std::string &name, size_t size = 0)
-{
-    return make_column<Type>(name, { size, utils::constraints::PRIMARY_KEY | utils::constraints::NOT_NULL});
-}
-
-template <>
-column make_pk_column<std::string>(const std::string &name, size_t size);
-
-template < typename Type >
-column make_fk_column(const std::string &name, size_t size, const std::string &ref_table, const std::string &ref_column)
-{
-    return {name, data_type_traits<Type>::builtin_type(size), ref_table, ref_column, { size, utils::constraints::FOREIGN_KEY }};
-}
-
-template < typename Type >
-[[maybe_unused]] column make_fk_column(const std::string &name, const std::string &ref_table, const std::string &ref_column)
-{
-    return {name, data_type_traits<Type>::builtin_type(0), 0, ref_table, ref_column, { 0, utils::constraints::FOREIGN_KEY }};
-}
-
-template <>
-column make_fk_column<std::string>(const std::string &name, size_t size, const std::string &ref_table, const std::string &ref_column);
-
 }
 #endif //QUERY_COLUMN_HPP

include/matador/sql/column_definition.hpp

@@ -0,0 +1,173 @@
+#ifndef QUERY_COLUMN_DEFINITION_HPP
+#define QUERY_COLUMN_DEFINITION_HPP
+
+#include "matador/sql/any_type.hpp"
+#include "matador/sql/any_type_to_visitor.hpp"
+#include "matador/sql/data_type_traits.hpp"
+
+#include "matador/utils/field_attributes.hpp"
+
+#include <optional>
+#include <vector>
+
+namespace matador::sql {
+
+enum class null_option : uint8_t {
+  NULLABLE, NOT_NULL
+};
+
+class column_definition {
+public:
+  explicit column_definition(const char *name); // NOLINT(*-explicit-constructor)
+  explicit column_definition(std::string name); // NOLINT(*-explicit-constructor)
+
+  column_definition(const column_definition&) = default;
+  column_definition& operator=(const column_definition&) = default;
+  column_definition(column_definition&&) noexcept = default;
+  column_definition& operator=(column_definition&&) noexcept = default;
+
+  template<typename Type>
+  explicit column_definition(std::string name, utils::field_attributes attr)
+  : column_definition(std::move(name), data_type_traits<Type>::builtin_type(attr.size()), attr)
+  {}
+
+  template<typename Type>
+  column_definition(std::string name, const Type &, utils::field_attributes attr, null_option null_opt)
+  : column_definition(std::move(name), data_type_traits<Type>::builtin_type(attr.size()), attr, null_opt)
+  {}
+
+  column_definition(std::string name, data_type_t type, utils::field_attributes attr, null_option null_opt, size_t index = 0);
+
+  template<typename Type>
+  column_definition(std::string name, std::string ref_table, std::string ref_column, utils::field_attributes attr, null_option null_opt)
+  : column_definition(std::move(name), data_type_traits<Type>::builtin_type(attr.size()), ref_table, ref_column, attr, null_opt)
+  {}
+
+  column_definition(std::string name, data_type_t type, size_t index, std::string ref_table, std::string ref_column, utils::field_attributes attr, null_option null_opt);
+
+  [[nodiscard]] const std::string& name() const;
+  [[nodiscard]] int index() const;
+  [[nodiscard]] const utils::field_attributes& attributes() const;
+  [[nodiscard]] bool is_nullable() const;
+  [[nodiscard]] data_type_t type() const;
+  [[nodiscard]] const std::string& ref_table() const;
+  [[nodiscard]] const std::string& ref_column() const;
+
+  [[nodiscard]] bool is_integer() const;
+  [[nodiscard]] bool is_floating_point() const;
+  [[nodiscard]] bool is_bool() const;
+  [[nodiscard]] bool is_string() const;
+  [[nodiscard]] bool is_varchar() const;
+  [[nodiscard]] bool is_blob() const;
+  [[nodiscard]] bool is_null() const;
+  [[nodiscard]] bool is_unknown() const;
+
+  void type(data_type_t type);
+
+  template< typename Type >
+  [[nodiscard]] bool is_type_of() const {
+    return std::holds_alternative<Type>(value_);
+  }
+
+  [[nodiscard]] std::string str() const;
+
+  template<typename Type>
+  void set(const Type &value, const utils::field_attributes &attr = utils::null_attributes)
+  {
+    type_ = data_type_traits<Type>::builtin_type(attr.size());
+    attributes_ = attr;
+    value_ = value;
+  }
+
+  void set(const std::string &value, const utils::field_attributes &attr)
+  {
+    type_ = data_type_traits<std::string>::builtin_type(attr.size());
+    attributes_ = attr;
+    value_ = value;
+  }
+
+  void set(const char *value, const utils::field_attributes &attr)
+  {
+    type_ = data_type_traits<std::string>::builtin_type(attr.size());
+    attributes_ = attr;
+    value_ = value;
+  }
+
+  template<class Type>
+  Type as() const
+  {
+    const Type* ptr= std::get_if<Type>(&value_);
+    if (ptr) {
+      return *ptr;
+    }
+    any_type_to_visitor<Type> visitor;
+    std::visit(visitor, const_cast<any_type&>(value_));
+    return visitor.result;
+  }
+
+  friend std::ostream& operator<<(std::ostream &out, const column_definition &col);
+
+private:
+  template<class Operator>
+  void process(Operator &op)
+  {
+    op.on_attribute(name_.c_str(), value_, type_, attributes_);
+  }
+
+  using data_type_index = std::vector<data_type_t>;
+
+private:
+  static const data_type_index data_type_index_;
+
+  std::string name_;
+  int index_{-1};
+  utils::field_attributes attributes_;
+  null_option null_option_{null_option::NOT_NULL};
+  data_type_t type_{data_type_t::type_unknown};
+  any_type value_;
+  std::string ref_table_;
+  std::string ref_column_;
+};
+
+/**
+ * User defined literal to have a shortcut creating a column object
+ * @param name Name of the column
+ * @param len Length of the column name
+ * @return A column object with given name
+ */
+column_definition make_column(const std::string &name, data_type_t type, utils::field_attributes attr = utils::null_attributes, null_option null_opt = null_option::NOT_NULL);
+
+template < typename Type >
+column_definition make_column(const std::string &name, utils::field_attributes attr = utils::null_attributes, null_option null_opt = null_option::NOT_NULL)
+{
+    return make_column(name, data_type_traits<Type>::builtin_type(0), attr, null_opt);
+}
+template <>
+column_definition make_column<std::string>(const std::string &name, utils::field_attributes attr, null_option null_opt);
+
+template < typename Type >
+column_definition make_pk_column(const std::string &name, size_t size = 0)
+{
+    return make_column<Type>(name, { size, utils::constraints::PRIMARY_KEY });
+}
+
+template <>
+column_definition make_pk_column<std::string>(const std::string &name, size_t size);
+
+template < typename Type >
+column_definition make_fk_column(const std::string &name, size_t size, const std::string &ref_table, const std::string &ref_column)
+{
+    return {name, data_type_traits<Type>::builtin_type(size), ref_table, ref_column, { size, utils::constraints::FOREIGN_KEY }};
+}
+
+template < typename Type >
+[[maybe_unused]] column_definition make_fk_column(const std::string &name, const std::string &ref_table, const std::string &ref_column)
+{
+    return {name, data_type_traits<Type>::builtin_type(0), 0, ref_table, ref_column, { 0, utils::constraints::FOREIGN_KEY }, null_option::NOT_NULL};
+}
+
+template <>
+column_definition make_fk_column<std::string>(const std::string &name, size_t size, const std::string &ref_table, const std::string &ref_column);
+
+}
+#endif //QUERY_COLUMN_DEFINITION_HPP

include/matador/sql/column_definition_generator.hpp

@@ -0,0 +1,133 @@
+#ifndef QUERY_COLUMN_DEFINITION_GENERATOR_HPP
+#define QUERY_COLUMN_DEFINITION_GENERATOR_HPP
+
+#include "matador/sql/column_definition.hpp"
+#include "matador/sql/data_type_traits.hpp"
+
+#include "matador/utils/access.hpp"
+#include "matador/utils/field_attributes.hpp"
+#include "matador/utils/foreign_attributes.hpp"
+
+#include <typeindex>
+#include <vector>
+
+namespace matador::sql {
+
+class schema;
+
+class fk_column_generator
+{
+public:
+  fk_column_generator() = default;
+
+  template<class Type>
+  column_definition generate(const char *id, Type &x, const std::string &ref_table, const std::string &ref_column)
+  {
+    utils::access::process(*this, x);
+    return column_definition{id, type_, 0, ref_table, ref_column, {utils::constraints::FOREIGN_KEY }, null_option::NOT_NULL};
+  }
+
+  template<typename ValueType>
+  void on_primary_key(const char *, ValueType &/*pk*/, typename std::enable_if<std::is_integral<ValueType>::value && !std::is_same<bool, ValueType>::value>::type* = 0)
+  {
+    type_ = data_type_traits<ValueType>::builtin_type(0);
+  }
+  void on_primary_key(const char * /*id*/, std::string &/*pk*/, size_t size);
+  void on_revision(const char * /*id*/, unsigned long long &/*rev*/) {}
+  template < class Type >
+  void on_attribute(const char * /*id*/, Type &/*x*/, const utils::field_attributes &/*attr*/ = utils::null_attributes) {}
+  void on_attribute(const char * /*id*/, char * /*x*/, const utils::field_attributes &/*attr*/ = utils::null_attributes) {}
+  template<class Pointer>
+  void on_belongs_to(const char * /*id*/, Pointer &/*x*/, const utils::foreign_attributes &/*attr*/) {}
+  template<class Pointer>
+  void on_has_one(const char * /*id*/, Pointer &/*x*/, const utils::foreign_attributes &/*attr*/) {}
+  template<class ContainerType>
+  void on_has_many(ContainerType &, const char *, const utils::foreign_attributes &/*attr*/) {}
+  template<class ContainerType>
+  void on_has_many_to_many(const char *id, ContainerType &c, const char *join_column, const char *inverse_join_column, const utils::foreign_attributes &/*attr*/) {}
+  template<class ContainerType>
+  void on_has_many_to_many(const char *id, ContainerType &c, const utils::foreign_attributes &/*attr*/) {}
+
+private:
+  data_type_t type_{};
+};
+
+class column_definition_generator
+{
+private:
+  column_definition_generator(std::vector<column_definition> &columns, const schema &repo);
+
+public:
+  ~column_definition_generator() = default;
+
+  template < class Type >
+  static std::vector<column_definition> generate(const schema &repo)
+  {
+    std::vector<column_definition> columns;
+    column_definition_generator gen(columns, repo);
+    Type obj;
+    matador::utils::access::process(gen, obj);
+    return std::move(columns);
+  }
+
+  template < class V >
+  void on_primary_key(const char *, V &x, typename std::enable_if<std::is_integral<V>::value && !std::is_same<bool, V>::value>::type* = 0);
+  void on_primary_key(const char *id, std::string &pk, size_t size);
+  void on_revision(const char *id, unsigned long long &rev);
+
+  template<typename Type>
+  void on_attribute(const char *id, Type &x, const utils::field_attributes &attr = utils::null_attributes);
+
+  template<typename Type>
+  void on_attribute(const char *id, std::optional<Type> &x, const utils::field_attributes &attr = utils::null_attributes);
+
+  template<class Pointer>
+  void on_belongs_to(const char *id, Pointer &x, const utils::foreign_attributes &/*attr*/)
+  {
+    const auto [ref_table, ref_column] = determine_foreign_ref(std::type_index(typeid(typename Pointer::value_type)));
+    columns_.push_back(fk_column_generator_.generate(id, *x, ref_table, ref_column));
+  }
+  template<class Pointer>
+  void on_has_one(const char *id, Pointer &x, const utils::foreign_attributes &/*attr*/)
+  {
+    const auto [ref_table, ref_column] = determine_foreign_ref(std::type_index(typeid(typename Pointer::value_type)));
+    columns_.push_back(fk_column_generator_.generate(id, *x, ref_table, ref_column));
+  }
+  template<class ContainerType>
+  void on_has_many(ContainerType &, const char *, const utils::foreign_attributes &/*attr*/) {}
+  template<class ContainerType>
+  void on_has_many_to_many(const char *id, ContainerType &c, const char *join_column, const char *inverse_join_column, const utils::foreign_attributes &/*attr*/) {}
+  template<class ContainerType>
+  void on_has_many_to_many(const char *id, ContainerType &c, const utils::foreign_attributes &/*attr*/) {}
+
+private:
+  std::pair<std::string, std::string> determine_foreign_ref(const std::type_index &ti);
+
+private:
+  size_t index_ = 0;
+  std::vector<column_definition> &columns_;
+  const schema &repo_;
+
+  fk_column_generator fk_column_generator_;
+};
+
+template<typename V>
+void column_definition_generator::on_primary_key(const char *id, V &x, typename std::enable_if<std::is_integral<V>::value && !std::is_same<bool, V>::value>::type*)
+{
+  on_attribute(id, x, { utils::constraints::PRIMARY_KEY });
+}
+
+template<typename Type>
+void column_definition_generator::on_attribute(const char *id, Type &x, const utils::field_attributes &attr)
+{
+  columns_.emplace_back(id, x, attr, null_option::NOT_NULL);
+}
+
+template<typename Type>
+void column_definition_generator::on_attribute(const char *id, std::optional<Type> &x, const utils::field_attributes &attr)
+{
+  columns_.emplace_back(id, data_type_traits<Type>::builtin_type(attr.size()), attr, null_option::NULLABLE);
+}
+
+}
+#endif //QUERY_COLUMN_DEFINITION_GENERATOR_HPP

include/matador/sql/column_generator.hpp

@@ -1,119 +1,128 @@
 #ifndef QUERY_COLUMN_GENERATOR_HPP
 #define QUERY_COLUMN_GENERATOR_HPP
 
-#include "matador/sql/column.hpp"
-#include "matador/sql/types.hpp"
-
 #include "matador/utils/access.hpp"
 #include "matador/utils/field_attributes.hpp"
+#include "matador/utils/foreign_attributes.hpp"
 
-#include <typeindex>
+#include "matador/sql/column.hpp"
+#include "matador/sql/schema.hpp"
+
+#include <string>
 #include <vector>
+#include <stack>
 
 namespace matador::sql {
 
-class table_repository;
-
-class fk_column_generator
-{
-public:
-  fk_column_generator() = default;
-
-  template<class Type>
-  column generate(const char *id, Type &x, const std::string &ref_table, const std::string &ref_column)
-  {
-    utils::access::process(*this, x);
-    return column{id, type_, 0, ref_table, ref_column, { utils::constraints::FOREIGN_KEY }};
-  }
-
-  template<typename ValueType>
-  void on_primary_key(const char *, ValueType &/*pk*/, typename std::enable_if<std::is_integral<ValueType>::value && !std::is_same<bool, ValueType>::value>::type* = 0)
-  {
-    type_ = data_type_traits<ValueType>::builtin_type(0);
-  }
-  void on_primary_key(const char * /*id*/, std::string &/*pk*/, size_t size);
-  void on_revision(const char * /*id*/, unsigned long long &/*rev*/) {}
-  template < class Type >
-  void on_attribute(const char * /*id*/, Type &/*x*/, const utils::field_attributes &/*attr*/ = utils::null_attributes) {}
-  void on_attribute(const char * /*id*/, char * /*x*/, const utils::field_attributes &/*attr*/ = utils::null_attributes) {}
-  template<class Pointer>
-  void on_belongs_to(const char * /*id*/, Pointer &/*x*/, utils::cascade_type) {}
-  template<class Pointer>
-  void on_has_one(const char * /*id*/, Pointer &/*x*/, utils::cascade_type) {}
-  template<class ContainerType>
-  void on_has_many(const char *, ContainerType &, const char *, const char *, utils::cascade_type) {}
-  template<class ContainerType>
-  void on_has_many(const char *, ContainerType &, utils::cascade_type) {}
-
-private:
-  data_type_t type_{};
-};
-
 class column_generator
 {
 private:
-  column_generator(std::vector<column> &columns, const table_repository &repo);
+  column_generator(std::vector<column> &column_infos,
+                   const sql::schema &ts,
+                   const std::string &table_name,
+                   bool force_lazy);
 
 public:
   ~column_generator() = default;
 
   template < class Type >
-  static std::vector<column> generate(const table_repository &repo)
+  static std::vector<column> generate(const sql::schema &ts, bool force_lazy = false)
   {
+    const auto info = ts.info<Type>();
+    if (!info) {
+      return {};
+    }
     std::vector<column> columns;
-    column_generator gen(columns, repo);
+    column_generator gen(columns, ts, info.value().name, force_lazy);
     Type obj;
     matador::utils::access::process(gen, obj);
     return std::move(columns);
   }
 
   template < class V >
-  void on_primary_key(const char *, V &x, typename std::enable_if<std::is_integral<V>::value && !std::is_same<bool, V>::value>::type* = 0);
+  void on_primary_key(const char *id, V &, typename std::enable_if<std::is_integral<V>::value && !std::is_same<bool, V>::value>::type* = 0)
-  void on_primary_key(const char *id, std::string &pk, size_t size);
+  {
-  void on_revision(const char *id, unsigned long long &rev);
+    push(id);
+  }
+  void on_primary_key(const char *id, std::string &, size_t);
+  void on_revision(const char *id, unsigned long long &/*rev*/);
 
   template<typename Type>
-  void on_attribute(const char *id, Type &x, const utils::field_attributes &attr = utils::null_attributes);
+  void on_attribute(const char *id, Type &, const utils::field_attributes &/*attr*/ = utils::null_attributes)
+  {
+    push(id);
+  }
 
   template<class Pointer>
-  void on_belongs_to(const char *id, Pointer &x, utils::cascade_type)
+  void on_belongs_to(const char *id, Pointer &, const utils::foreign_attributes &attr)
   {
-    const auto [ref_table, ref_column] = determine_foreign_ref(std::type_index(typeid(typename Pointer::value_type)));
+    if (attr.fetch() == utils::fetch_type::LAZY || force_lazy_) {
-    columns_.push_back(fk_column_generator_.generate(id, *x, ref_table, ref_column));
+      push(id);
+    } else {
+      const auto info = table_schema_.info<typename Pointer::value_type>();
+      if (!info) {
+        return;
+      }
+      table_name_stack_.push(info.value().name);
+      typename Pointer::value_type obj;
+      matador::utils::access::process(*this, obj);
+      table_name_stack_.pop();
+    }
   }
   template<class Pointer>
-  void on_has_one(const char *id, Pointer &x, utils::cascade_type)
+  void on_has_one(const char *id, Pointer &, const utils::foreign_attributes &attr)
   {
-    const auto [ref_table, ref_column] = determine_foreign_ref(std::type_index(typeid(typename Pointer::value_type)));
+    if (attr.fetch() == utils::fetch_type::LAZY || force_lazy_) {
-    columns_.push_back(fk_column_generator_.generate(id, *x, ref_table, ref_column));
+      push(id);
+    } else {
+      const auto info = table_schema_.info<typename Pointer::value_type>();
+      if (!info) {
+        return;
+      }
+      table_name_stack_.push(info.value().name);
+      typename Pointer::value_type obj;
+      matador::utils::access::process(*this, obj);
+      table_name_stack_.pop();
+    }
   }
   template<class ContainerType>
-  void on_has_many(const char *, ContainerType &, const char *, const char *, utils::cascade_type) {}
+  void on_has_many(ContainerType &, const char *, const utils::foreign_attributes &attr)
+  {
+    if (attr.fetch() == utils::fetch_type::LAZY || force_lazy_) {
+      return;
+    }
+    const auto info = table_schema_.info<typename ContainerType::value_type::value_type>();
+    if (!info) {
+      return;
+    }
+
+    table_name_stack_.push(info.value().name);
+    typename ContainerType::value_type::value_type obj;
+    matador::utils::access::process(*this, obj);
+    table_name_stack_.pop();
+  }
+
   template<class ContainerType>
-  void on_has_many(const char *, ContainerType &, utils::cascade_type) {}
+  void on_has_many_to_many(const char *id, ContainerType &c, const char *join_column, const char *inverse_join_column, const utils::foreign_attributes &attr)
+  {
+  }
+
+  template<class ContainerType>
+  void on_has_many_to_many(const char *id, ContainerType &c, const utils::foreign_attributes &attr)
+  {
+  }
 
 private:
-  std::pair<std::string, std::string> determine_foreign_ref(const std::type_index &ti);
+  void push(const std::string &column_name);
 
 private:
-  size_t index_ = 0;
+  std::stack<std::string> table_name_stack_;
-  std::vector<column> &columns_;
+  std::vector<column> &column_infos_;
-  const table_repository &repo_;
+  const sql::schema &table_schema_;
-
+  int column_index{0};
-  fk_column_generator fk_column_generator_;
+  bool force_lazy_{false};
 };
 
-template<typename V>
-void column_generator::on_primary_key(const char *id, V &x, typename std::enable_if<std::is_integral<V>::value && !std::is_same<bool, V>::value>::type*)
-{
-  on_attribute(id, x, { utils::constraints::PRIMARY_KEY });
 }
 
-template<typename Type>
-void column_generator::on_attribute(const char *id, Type &x, const utils::field_attributes &attr)
-{
-  columns_.emplace_back(id, x, attr);
-}
-
-}
 #endif //QUERY_COLUMN_GENERATOR_HPP

include/matador/sql/column_name_generator.hpp

@@ -1,65 +0,0 @@
-#ifndef QUERY_COLUMN_NAME_GENERATOR_HPP
-#define QUERY_COLUMN_NAME_GENERATOR_HPP
-
-#include "matador/utils/access.hpp"
-#include "matador/utils/field_attributes.hpp"
-
-#include <string>
-#include <vector>
-
-namespace matador::sql {
-
-class column_name_generator
-{
-private:
-  explicit column_name_generator(std::vector<std::string> &column_names);
-
-public:
-  ~column_name_generator() = default;
-
-  template < class Type >
-  static std::vector<std::string> generate()
-  {
-    std::vector<std::string> columns;
-    column_name_generator gen(columns);
-    Type obj;
-    matador::utils::access::process(gen, obj);
-    return std::move(columns);
-  }
-
-  template < class V >
-  void on_primary_key(const char *id, V &, typename std::enable_if<std::is_integral<V>::value && !std::is_same<bool, V>::value>::type* = 0)
-  {
-    column_names_.emplace_back(id);
-  }
-  void on_primary_key(const char *id, std::string &, size_t);
-  void on_revision(const char *id, unsigned long long &/*rev*/);
-
-  template<typename Type>
-  void on_attribute(const char *id, Type &, const utils::field_attributes &/*attr*/ = utils::null_attributes)
-  {
-    column_names_.emplace_back(id);
-  }
-
-  template<class Pointer>
-  void on_belongs_to(const char *id, Pointer &, utils::cascade_type)
-  {
-    column_names_.emplace_back(id);
-  }
-  template<class Pointer>
-  void on_has_one(const char *id, Pointer &, utils::cascade_type)
-  {
-    column_names_.emplace_back(id);
-  }
-  template<class ContainerType>
-  void on_has_many(const char *, ContainerType &, const char *, const char *, utils::cascade_type) {}
-  template<class ContainerType>
-  void on_has_many(const char *, ContainerType &, utils::cascade_type) {}
-
-private:
-  std::vector<std::string> &column_names_;
-};
-
-}
-
-#endif //QUERY_COLUMN_NAME_GENERATOR_HPP

include/matador/sql/condition.hpp

@@ -1,12 +1,15 @@
 #ifndef QUERY_CONDITION_HPP
 #define QUERY_CONDITION_HPP
 
+#include "matador/sql/any_type_to_string_visitor.hpp"
+#include "matador/sql/query_result.hpp"
 #include "matador/sql/basic_condition.hpp"
 #include "matador/sql/dialect.hpp"
 #include "matador/sql/placeholder.hpp"
 #include "matador/sql/query_context.hpp"
 
 #include <memory>
+#include <utility>
 
 namespace matador::sql {
 
@@ -25,6 +28,8 @@ namespace matador::sql {
 
 /// @cond MATADOR_DEV
 
+class query_select;
+
 template<class L, class R, class Enabled = void>
 class condition;
 
@@ -36,12 +41,13 @@ public:
 
     placeholder value;
 
-    std::string evaluate(dialect &d, query_context &query) const override;
+    std::string evaluate(const dialect &d, query_context &query) const override;
 };
 
 template<class T>
 class condition<column, T, typename std::enable_if<
   std::is_scalar<T>::value &&
+  !std::is_enum<T>::value &&
   !std::is_same<std::string, T>::value &&
   !std::is_same<const char*, T>::value>::type> : public basic_column_condition
 {
@@ -53,10 +59,10 @@ public:
 
   T value;
 
-  std::string evaluate(dialect &d, query_context &query) const override
+  std::string evaluate(const dialect &d, query_context &query) const override
   {
-    query.bind_vars.emplace_back(field_.name());
+    query.bind_vars.emplace_back(field_.name);
-    return d.prepare_identifier(field_.name()) + " " + operand + " " + std::to_string(value);
+    return d.prepare_identifier(field_) + " " + operand + " " + std::to_string(value);
   }
 };
 
@@ -73,18 +79,40 @@ public:
 
   T value;
 
-  std::string evaluate(dialect &d, query_context &query) const override
+  std::string evaluate(const dialect &d, query_context &query) const override
   {
-    query.bind_vars.emplace_back(field_.name());
+    query.bind_vars.emplace_back(field_.name);
-    return d.prepare_identifier(field_.name()) + " " + operand + " '" + value + "'";
+    return d.prepare_identifier(field_) + " " + operand + " '" + value + "'";
   }
 };
 
 template<class T>
-class condition<T, column, typename std::enable_if<
+class condition<column, T, std::enable_if_t<std::is_enum_v<T>>> final : public basic_column_condition
-  std::is_scalar<T>::value &&
+{
-  !std::is_same<std::string, T>::value &&
+public:
-  !std::is_same<const char*, T>::value>::type> : public basic_column_condition
+  condition(const column &fld, basic_condition::operand_t op, T val)
+    : basic_column_condition(fld, op)
+    , value(val)
+  { }
+
+  T value;
+
+  std::string evaluate(const dialect &d, query_context &query) const override
+  {
+    auto at = data_type_traits<T>::create_value(value);
+    any_type_to_string_visitor value_to_string(d, query);
+    std::visit(value_to_string, at);
+    return value_to_string.result + " " + operand + " " + d.prepare_identifier(field_);
+  }
+
+};
+
+
+template<class T>
+class condition<T, column, std::enable_if_t<
+  std::is_scalar_v<T> &&
+  !std::is_same_v<std::string, T> &&
+  !std::is_same_v<const char*, T>>> final : public basic_column_condition
 {
 public:
   condition(T val, basic_condition::operand_t op, const column &fld)
@@ -94,9 +122,9 @@ public:
 
   T value;
 
-  std::string evaluate(dialect &d, query_context &query) const override
+  std::string evaluate(const dialect &d, query_context &query) const override
   {
-    return std::to_string(value) + " " + operand + " " + d.prepare_identifier(field_.name());
+    return std::to_string(value) + " " + operand + " " + d.prepare_identifier(field_);
   }
 };
 
@@ -113,9 +141,9 @@ public:
 
   T value;
 
-  std::string evaluate(dialect &d, query_context &query) const override
+  std::string evaluate(const dialect &d, query_context &query) const override
   {
-    return "'" + std::to_string(value) + "' " + operand + " " + d.prepare_identifier(field_.name());
+    return "'" + std::to_string(value) + "' " + operand + " " + d.prepare_identifier(field_);
   }
 };
 
@@ -155,13 +183,13 @@ public:
    * @param d The d used to evaluate
    * @return A condition IN part of the query
    */
-  std::string evaluate(dialect &d, query_context &query) const override {
+  std::string evaluate(const dialect &d, query_context &query) const override {
     auto count = size();
     for (size_t i = 0; i < count; ++i) {
-      query.bind_vars.emplace_back(field_.name());
+      query.bind_vars.emplace_back(field_.name);
     }
 
-    std::string result = d.prepare_identifier(field_.name()) + " IN (";
+    std::string result = d.prepare_identifier(field_) + " IN (";
     if (args_.size() < 2) {
       for (const auto &val : args_) {
         result.append(std::to_string(val));
@@ -214,7 +242,7 @@ public:
    * @param op Operand of the condition
    * @param q The query to be evaluated to the IN arguments
    */
-  condition(column col, basic_condition::operand_t op, query_context &q);
+  condition(column col, basic_condition::operand_t op, const query_context &q);
 
   /**
    * @brief Evaluates the condition
@@ -225,10 +253,10 @@ public:
    * @param d The d used to evaluate
    * @return A condition IN part of the query
    */
-  std::string evaluate(dialect &d, query_context &query) const override;
+  std::string evaluate(const dialect &d, query_context &query) const override;
 
 private:
-  query_context &query_;
+  query_context query_;
 };
 
 /**
@@ -260,10 +288,10 @@ public:
    * @param d The d used to evaluate
    * @return A condition BETWEEN part of the query
    */
-  std::string evaluate(dialect &d, query_context &query) const override {
+  std::string evaluate(const dialect &d, query_context &query) const override {
-    query.bind_vars.emplace_back(field_.name());
+    query.bind_vars.emplace_back(field_.name);
-    query.bind_vars.emplace_back(field_.name());
+    query.bind_vars.emplace_back(field_.name);
-    return d.prepare_identifier(field_.name()) + " BETWEEN " + std::to_string(range_.first) + " AND " + std::to_string(range_.second);
+    return d.prepare_identifier(field_) + " BETWEEN " + std::to_string(range_.first) + " AND " + std::to_string(range_.second);
   }
 
 private:
@@ -302,7 +330,7 @@ public:
    * @param d The d used to evaluate
    * @return The evaluated string based on the compile type
    */
-  std::string evaluate(dialect &d, query_context &query) const override
+  std::string evaluate(const dialect &d, query_context &query) const override
   {
     // ensure the numbering order for host vars
     auto cl = left.evaluate(d, query);
@@ -345,7 +373,7 @@ public:
    * @param d The d used to evaluate
    * @return The evaluated string based on the compile type
    */
-  std::string evaluate(dialect &d, query_context &query) const override
+  std::string evaluate(const dialect &d, query_context &query) const override
   {
     return operand + " (" + cond.evaluate(d) + ")";
   }
@@ -355,6 +383,28 @@ private:
   std::string operand;
 };
 
+template<>
+class condition<column, column> : public basic_column_condition
+{
+public:
+  condition(const column &a, basic_condition::operand_t op, column b)
+  : basic_column_condition(a, op)
+  , other_column_(std::move(b)) {}
+  /**
+   * @brief Evaluates the condition
+   *
+   * @param d The d used to evaluate
+   * @return The evaluated string based on the compile type
+   */
+  std::string evaluate(const dialect &d, query_context &query) const override
+  {
+    return d.prepare_identifier(field_) + " " + operand + " " + d.prepare_identifier(other_column_);
+  }
+
+private:
+  column other_column_;
+};
+
 /**
  * @file condition.hpp
  * @brief Contains functions to create query conditions
@@ -392,7 +442,8 @@ condition<column, std::initializer_list<V>> in(const column &col, std::initializ
  * @param q The query to be executes as sub select
  * @return The condition object
  */
-condition<column, query_context> in(const column &col, query_context &&q);
+condition<column, query_context> in(const column &col, const query_context &q);
+condition<column, query_context> in(const column &col, const query_select &q);
 
 /**
  * @brief Creates a between condition.
@@ -441,6 +492,8 @@ condition<column, T> operator==(const column &col, T val)
   return condition<column, T>(col, basic_condition::operand_t::EQUAL, val);
 }
 
+condition<column, column> operator==(const column &a, const column &b);
+
 /**
  * @brief Condition equality method for a column and a query
  *

include/matador/sql/connection.hpp

@@ -4,6 +4,7 @@
 #include "matador/sql/connection_info.hpp"
 #include "matador/sql/connection_impl.hpp"
 #include "matador/sql/dialect.hpp"
+#include "matador/sql/query.hpp"
 #include "matador/sql/query_context.hpp"
 #include "matador/sql/query_result.hpp"
 #include "matador/sql/record.hpp"
@@ -15,6 +16,8 @@
 
 namespace matador::sql {
 
+class schema;
+
 class connection
 {
 public:
@@ -23,7 +26,6 @@ public:
   connection(const connection &x);
   connection& operator=(const connection &x);
   connection(connection &&x) noexcept = default;
-  connection& operator=(connection &&x) noexcept = default;
   ~connection();
 
   void open();
@@ -31,18 +33,25 @@ public:
   [[nodiscard]] bool is_open() const;
   [[nodiscard]] const connection_info& info() const;
 
-  [[nodiscard]] record describe(const std::string &table_name) const;
+  [[nodiscard]] std::vector<sql::column_definition> describe(const std::string &table_name) const;
   [[nodiscard]] bool exists(const std::string &schema_name, const std::string &table_name) const;
+  [[nodiscard]] bool exists(const std::string &table_name) const;
 
+  sql::query query(const sql::schema &schema) const;
+
+  query_result<record> fetch(const query_context &q) const;
   [[nodiscard]] std::unique_ptr<query_result_impl> fetch(const std::string &sql) const;
   [[nodiscard]] size_t execute(const std::string &sql) const;
 
   statement prepare(query_context &&query) const;
 
+  const class dialect& dialect() const;
+
 private:
   connection_info connection_info_;
   std::unique_ptr<connection_impl> connection_;
   utils::logger logger_;
+  const class dialect &dialect_;
 };
 
 }

include/matador/sql/connection_impl.hpp

@@ -26,7 +26,7 @@ public:
   virtual std::unique_ptr<query_result_impl> fetch(const std::string &stmt) = 0;
   virtual std::unique_ptr<statement_impl> prepare(query_context context) = 0;
 
-  virtual record describe(const std::string &table) = 0;
+  virtual std::vector<sql::column_definition> describe(const std::string &table) = 0;
   virtual bool exists(const std::string &schema_name, const std::string &table_name) = 0;
 
 protected:

include/matador/sql/connection_pool.hpp

@@ -7,6 +7,7 @@
 #include <mutex>
 #include <string>
 #include <optional>
+#include <condition_variable>
 #include <thread>
 #include <unordered_map>
 
@@ -73,31 +74,34 @@ public:
   using connection_pointer = connection_ptr<Connection>;
 
 public:
-  connection_pool(const std::string &dns, unsigned int count)
+  connection_pool(const std::string &dns, size_t count)
   : info_(connection_info::parse(dns)) {
     connection_repo_.reserve(count);
-    for (auto i = 0U; i < count; ++i) {
+    while (count) {
-      connection_repo_.emplace_back(i+1, info_);
+      connection_repo_.emplace_back(count, info_);
       auto &conn = connection_repo_.back();
       idle_connections_.emplace(conn.first, &conn);
       conn.second.open();
+      --count;
     }
   }
 
   connection_pointer acquire() {
+    std::unique_lock<std::mutex> lock(mutex_);
+    while (idle_connections_.empty()) {
+      cv.wait(lock);
+    }
+
+    return get_next_connection();
+  }
+
+  connection_pointer try_acquire() {
     std::unique_lock<std::mutex> lock(mutex_);
     if (idle_connections_.empty()) {
       return {nullptr, this};
     }
 
-    pointer next_connection{nullptr};
+    return get_next_connection();
-    for (auto &item : idle_connections_) {
-      next_connection = item.second;
-      auto node = idle_connections_.extract(item.first);
-      inuse_connections_.insert(std::move(node));
-      break;
-    }
-    return {next_connection, this};
   }
 
   connection_pointer acquire(size_t id) {
@@ -150,8 +154,21 @@ public:
   const connection_info &info() const {
     return info_;
   }
+
+private:
+  connection_pointer get_next_connection() {
+    pointer next_connection{nullptr};
+    for (auto &item : idle_connections_) {
+      next_connection = item.second;
+      auto node = idle_connections_.extract(item.first);
+      inuse_connections_.insert(std::move(node));
+      break;
+    }
+    return {next_connection, this};
+  }
 private:
   mutable std::mutex mutex_;
+  std::condition_variable cv;
   std::vector<IdConnection<Connection>> connection_repo_;
   using pointer = IdConnection<Connection>*;
   using connection_map = std::unordered_map<size_t, pointer>;

include/matador/sql/convert.hpp

@@ -0,0 +1,124 @@
+#ifndef QUERY_CONVERT_HPP
+#define QUERY_CONVERT_HPP
+
+#include "matador/utils/types.hpp"
+
+#include <array>
+#include <charconv>
+#include <stdexcept>
+#include <string>
+#include <type_traits>
+
+namespace matador::sql {
+
+template < typename DestType, typename SourceType >
+void convert(DestType &dest, SourceType source, typename std::enable_if<std::is_same<DestType, SourceType>::value>::type* = nullptr)
+{
+  dest = source;
+}
+
+template < typename DestType, typename SourceType >
+void convert(DestType &dest, SourceType source, typename std::enable_if<std::is_integral<DestType>::value && std::is_arithmetic<SourceType>::value && !std::is_same<DestType, SourceType>::value>::type* = nullptr)
+{
+  dest = static_cast<DestType>(source);
+}
+
+template < typename DestType, typename SourceType >
+void convert(DestType &dest, SourceType source, typename std::enable_if<std::is_floating_point<DestType>::value && std::is_arithmetic<SourceType>::value && !std::is_same<DestType, SourceType>::value>::type* = nullptr)
+{
+  dest = static_cast<DestType>(source);
+}
+
+void convert(std::string &dest, bool source);
+
+template < typename SourceType >
+void convert(std::string &dest, SourceType source, typename std::enable_if<std::is_integral<SourceType>::value && !std::is_same<bool, SourceType>::value>::type* = nullptr)
+{
+  std::array<char, 128> buffer{};
+  auto [ptr, ec] = std::to_chars(buffer.data(), buffer.data() + buffer.size(), source, 10);
+  if (ec == std::errc{}) {
+    dest.assign(buffer.data(), ptr);
+  } else {
+    throw std::logic_error("couldn't convert value to std::string");
+  }
+}
+
+template < typename SourceType >
+void convert(std::string &dest, SourceType source, typename std::enable_if<std::is_floating_point<SourceType>::value>::type* = nullptr)
+{
+  std::array<char, 128> buffer{};
+  auto [ptr, ec] = std::to_chars(buffer.data(), buffer.data() + buffer.size(), source);
+  if (ec == std::errc{}) {
+    dest.assign(buffer.data(), ptr);
+  } else {
+    throw std::logic_error("couldn't convert value to std::string");
+  }
+}
+
+template < typename SourceType >
+void convert(utils::blob &dest, SourceType source, typename std::enable_if<!std::is_same<utils::blob, SourceType>::value>::type* = nullptr)
+{
+  throw std::logic_error("couldn't convert value to matador::utils::blob");
+}
+
+void convert(std::string &dest, const char* source);
+
+unsigned long long to_unsigned_long_long(const char *source);
+
+template < typename DestType >
+void convert(DestType &dest, const std::string &source, typename std::enable_if<std::is_integral<DestType>::value && std::is_unsigned<DestType>::value>::type* = nullptr)
+{
+  dest = to_unsigned_long_long(source.c_str());
+}
+
+template < typename DestType >
+void convert(DestType &dest, const char *source, typename std::enable_if<std::is_integral<DestType>::value && std::is_unsigned<DestType>::value>::type* = nullptr)
+{
+  dest = to_unsigned_long_long(source);
+}
+
+long long to_long_long(const char *source);
+
+template < typename DestType >
+void convert(DestType &dest, const std::string &source, typename std::enable_if<std::is_integral<DestType>::value && std::is_signed<DestType>::value>::type* = nullptr)
+{
+  dest = to_long_long(source.c_str());
+}
+
+template < typename DestType >
+void convert(DestType &dest, const char *source, typename std::enable_if<std::is_integral<DestType>::value && std::is_signed<DestType>::value>::type* = nullptr)
+{
+  dest = to_long_long(source);
+}
+
+long double to_double(const char *source);
+
+template < typename DestType >
+void convert(DestType &dest, const std::string &source, typename std::enable_if<std::is_floating_point<DestType>::value>::type* = nullptr)
+{
+  dest = to_double(source.c_str());
+}
+
+template < typename DestType >
+void convert(DestType &dest, const char *source, typename std::enable_if<std::is_floating_point<DestType>::value>::type* = nullptr)
+{
+  dest = to_double(source);
+}
+
+template < typename DestType >
+void convert(DestType &dest, bool source, typename std::enable_if<std::is_floating_point<DestType>::value>::type* = nullptr)
+{
+  dest = static_cast<DestType>(source);
+}
+
+template < typename DestType >
+void convert(DestType &dest, const utils::blob &data)
+{
+  throw std::logic_error("couldn't convert matador::utils::blob into destination type");
+}
+
+void convert(utils::blob &dest, const utils::blob &data);
+
+}
+
+#endif //QUERY_CONVERT_HPP

include/matador/sql/data_type_traits.hpp

@@ -1,8 +1,10 @@
-#ifndef QUERY_TYPES_HPP
+#ifndef QUERY_DATA_TYPE_TRAITS_HPP
-#define QUERY_TYPES_HPP
+#define QUERY_DATA_TYPE_TRAITS_HPP
 
 #include "matador/sql/any_type.hpp"
 
+#include "matador/utils/types.hpp"
+
 #include <cstdint>
 #include <string>
 
@@ -39,16 +41,6 @@ enum class data_type_t : uint8_t {
   type_unknown             /*!< Data type unknown */
 };
 
-enum class sql_function_t {
-  NONE,
-  COUNT,
-  AVG,
-  SUM,
-  MIN,
-  MAX
-};
-
-
 /**
  * @tparam T The type of the traits
  * @brief Type traits for database types
@@ -61,13 +53,22 @@ template < class Type, class Enable = void >
 struct data_type_traits;
 
 /// @cond MATADOR_DEV
+template <> struct data_type_traits<nullptr_t, void>
+{
+  inline static data_type_t builtin_type(std::size_t /*size*/) { return data_type_t::type_null; }
+  static void read_value(query_result_reader &reader, const char *id, size_t index, nullptr_t &/*value*/);
+  static void bind_value(parameter_binder &binder, size_t index, nullptr_t &/*value*/);
+  static void bind_result_value(result_parameter_binder &binder, size_t index, nullptr_t &/*value*/);
+  inline static any_type create_value(const char &value) { return value; }
+};
+
 template <> struct data_type_traits<char, void>
 {
   inline static data_type_t builtin_type(std::size_t /*size*/) { return data_type_t::type_char; }
   static void read_value(query_result_reader &reader, const char *id, size_t index, char &value);
   static void bind_value(parameter_binder &binder, size_t index, char &value);
   static void bind_result_value(result_parameter_binder &binder, size_t index, char &value);
-  inline static any_type create_value(char &value) { return value; }
+  inline static any_type create_value(const char &value) { return value; }
 };
 
 template <> struct data_type_traits<short, void>
@@ -76,7 +77,7 @@ template <> struct data_type_traits<short, void>
   static void read_value(query_result_reader &reader, const char *id, size_t index, short &value);
   static void bind_value(parameter_binder &binder, size_t index, short &value);
   static void bind_result_value(result_parameter_binder &binder, size_t index, short &value);
-  inline static any_type create_value(short &value) { return value; }
+  inline static any_type create_value(const short &value) { return value; }
 };
 
 template <> struct data_type_traits<int, void>
@@ -85,7 +86,7 @@ template <> struct data_type_traits<int, void>
   static void read_value(query_result_reader &reader, const char *id, size_t index, int &value);
   static void bind_value(parameter_binder &binder, size_t index, int &value);
   static void bind_result_value(result_parameter_binder &binder, size_t index, int &value);
-  inline static any_type create_value(int &value) { return value; }
+  inline static any_type create_value(const int &value) { return value; }
 };
 
 template <> struct data_type_traits<long, void>
@@ -94,7 +95,7 @@ template <> struct data_type_traits<long, void>
   static void read_value(query_result_reader &reader, const char *id, size_t index, long &value);
   static void bind_value(parameter_binder &binder, size_t index, long &value);
   static void bind_result_value(result_parameter_binder &binder, size_t index, long &value);
-  inline static any_type create_value(long &value) { return value; }
+  inline static any_type create_value(const long &value) { return value; }
 };
 
 template <> struct data_type_traits<long long, void>
@@ -103,7 +104,7 @@ template <> struct data_type_traits<long long, void>
   static void read_value(query_result_reader &reader, const char *id, size_t index, long long &value);
   static void bind_value(parameter_binder &binder, size_t index, long long &value);
   static void bind_result_value(result_parameter_binder &binder, size_t index, long long &value);
-  inline static any_type create_value(long long &value) { return value; }
+  inline static any_type create_value(const long long &value) { return value; }
 };
 
 template <> struct data_type_traits<unsigned char, void>
@@ -112,7 +113,7 @@ template <> struct data_type_traits<unsigned char, void>
   static void read_value(query_result_reader &reader, const char *id, size_t index, unsigned char &value);
   static void bind_value(parameter_binder &binder, size_t index, unsigned char &value);
   static void bind_result_value(result_parameter_binder &binder, size_t index, unsigned char &value);
-  inline static any_type create_value(unsigned char &value) { return value; }
+  inline static any_type create_value(const unsigned char &value) { return value; }
 };
 
 template <> struct data_type_traits<unsigned short, void>
@@ -121,7 +122,7 @@ template <> struct data_type_traits<unsigned short, void>
   static void read_value(query_result_reader &reader, const char *id, size_t index, unsigned short &value);
   static void bind_value(parameter_binder &binder, size_t index, unsigned short &value);
   static void bind_result_value(result_parameter_binder &binder, size_t index, unsigned short &value);
-  inline static any_type create_value(unsigned short &value) { return value; }
+  inline static any_type create_value(const unsigned short &value) { return value; }
 };
 
 template <> struct data_type_traits<unsigned int, void>
@@ -130,7 +131,7 @@ template <> struct data_type_traits<unsigned int, void>
   static void read_value(query_result_reader &reader, const char *id, size_t index, unsigned int &value);
   static void bind_value(parameter_binder &binder, size_t index, unsigned int &value);
   static void bind_result_value(result_parameter_binder &binder, size_t index, unsigned int &value);
-  inline static any_type create_value(unsigned int &value) { return value; }
+  inline static any_type create_value(const unsigned int &value) { return value; }
 };
 
 template <> struct data_type_traits<unsigned long, void>
@@ -139,7 +140,7 @@ template <> struct data_type_traits<unsigned long, void>
   static void read_value(query_result_reader &reader, const char *id, size_t index, unsigned long &value);
   static void bind_value(parameter_binder &binder, size_t index, unsigned long &value);
   static void bind_result_value(result_parameter_binder &binder, size_t index, unsigned long &value);
-  inline static any_type create_value(unsigned long &value) { return value; }
+  inline static any_type create_value(const unsigned long &value) { return value; }
 };
 
 template <> struct data_type_traits<unsigned long long, void>
@@ -148,7 +149,7 @@ template <> struct data_type_traits<unsigned long long, void>
   static void read_value(query_result_reader &reader, const char *id, size_t index, unsigned long long &value);
   static void bind_value(parameter_binder &binder, size_t index, unsigned long long &value);
   static void bind_result_value(result_parameter_binder &binder, size_t index, unsigned long long &value);
-  inline static any_type create_value(unsigned long long &value) { return value; }
+  inline static any_type create_value(const unsigned long long &value) { return value; }
 };
 
 template <> struct data_type_traits<bool, void>
@@ -157,7 +158,7 @@ template <> struct data_type_traits<bool, void>
   static void read_value(query_result_reader &reader, const char *id, size_t index, bool &value);
   static void bind_value(parameter_binder &binder, size_t index, bool &value);
   static void bind_result_value(result_parameter_binder &binder, size_t index, bool &value);
-  inline static any_type create_value(bool &value) { return value; }
+  inline static any_type create_value(const bool &value) { return value; }
 };
 
 template <> struct data_type_traits<float, void>
@@ -166,7 +167,7 @@ template <> struct data_type_traits<float, void>
   static void read_value(query_result_reader &reader, const char *id, size_t index, float &value);
   static void bind_result_value(result_parameter_binder &binder, size_t index, float &value);
   static void bind_value(parameter_binder &binder, size_t index, float &value);
-  inline static any_type create_value(float &value) { return value; }
+  inline static any_type create_value(const float &value) { return value; }
 };
 
 template <> struct data_type_traits<double, void>
@@ -175,7 +176,7 @@ template <> struct data_type_traits<double, void>
   static void read_value(query_result_reader &reader, const char *id, size_t index, double &value);
   static void bind_result_value(result_parameter_binder &binder, size_t index, double &value);
   static void bind_value(parameter_binder &binder, size_t index, double &value);
-  inline static any_type create_value(double &value) { return value; }
+  inline static any_type create_value(const double &value) { return value; }
 };
 
 template <> struct data_type_traits<const char*, void>
@@ -202,7 +203,16 @@ template <> struct data_type_traits<std::string, void>
   static void read_value(query_result_reader &reader, const char *id, size_t index, std::string &value, size_t size);
   static void bind_value(parameter_binder &binder, size_t index, std::string &value, size_t size = 0);
   static void bind_result_value(result_parameter_binder &binder, size_t index, std::string &value, size_t size = 0);
-  inline static any_type create_value(std::string &value) { return value; }
+  inline static any_type create_value(const std::string &value) { return value; }
+};
+
+template <> struct data_type_traits<utils::blob, void>
+{
+  inline static data_type_t builtin_type(std::size_t /*size*/) { return data_type_t::type_blob; }
+  static void read_value(query_result_reader &reader, const char *id, size_t index, utils::blob &value);
+  static void bind_value(parameter_binder &binder, size_t index, utils::blob &value);
+  static void bind_result_value(result_parameter_binder &binder, size_t index, utils::blob &value);
+  inline static any_type create_value(const utils::blob &value) { return value; }
 };
 
 //template <> struct data_type_traits<matador::date>
@@ -222,7 +232,7 @@ template <> struct data_type_traits<std::string, void>
 //};
 
 template < typename EnumType >
-struct data_type_traits<EnumType, typename std::enable_if<std::is_enum<EnumType>::value>::type>
+struct data_type_traits<EnumType, std::enable_if_t<std::is_enum_v<EnumType>>>
 {
   inline static data_type_t builtin_type(std::size_t /*size*/) { return data_type_t::type_int; }
   static void read_value(query_result_reader &reader, const char *id, size_t index, EnumType &value)
@@ -231,15 +241,17 @@ struct data_type_traits<EnumType, typename std::enable_if<std::is_enum<EnumType>
   }
   static void bind_value(parameter_binder &binder, size_t index, EnumType &value)
   {
-    data_type_traits<int>::bind_value(binder, index, (int&)value);
+    data_type_traits<int>::bind_value(binder, index, static_cast<int&>(value));
   }
   static void bind_result_value(result_parameter_binder &binder, size_t index, EnumType &value)
   {
-    data_type_traits<int>::bind_result_value(binder, index, (int&)value);
+    data_type_traits<int>::bind_result_value(binder, index, static_cast<int&>(value));
+  }
+  static any_type create_value(const EnumType &value) {
+      return static_cast<int>(value);
   }
-  inline static any_type create_value(EnumType &value) { return (int)value; }
 };
 /// @endcond
 
 }
-#endif //QUERY_TYPES_HPP
+#endif //QUERY_DATA_TYPE_TRAITS_HPP

include/matador/sql/dialect.hpp

@@ -1,7 +1,8 @@
 #ifndef QUERY_DIALECT_HPP
 #define QUERY_DIALECT_HPP
 
-#include "matador/sql/types.hpp"
+#include "matador/sql/column.hpp"
+#include "matador/sql/data_type_traits.hpp"
 
 #include <cstdint>
 #include <functional>
@@ -11,8 +12,6 @@
 
 namespace matador::sql {
 
-class column;
-
 class dialect final
 {
 public:
@@ -26,11 +25,15 @@ public:
     SELECT,
     TABLE,
     VALUES,
+    INSERT_VALUES,
     COLUMNS,
     COLUMN,
     FROM,
+    JOIN,
+    ON,
     INTO,
     WHERE,
+    WHERE_CLAUSE,
     AND,
     OR,
     LIKE,
@@ -43,6 +46,7 @@ public:
     OFFSET,
     DISTINCT,
     SET,
+    UPDATE_VALUES,
     NOT_NULL,
     PRIMARY_KEY,
     BEGIN,
@@ -51,6 +55,8 @@ public:
     START_QUOTE,
     END_QUOTE,
     STRING_QUOTE,
+    BEGIN_BINARY_DATA,
+    END_BINARY_DATA,
     NONE
   };
 
@@ -81,6 +87,7 @@ public:
  * @return The prepared string
  */
   [[nodiscard]] std::string prepare_identifier(const column &col) const;
+  [[nodiscard]] std::string prepare_identifier_string(const std::string &col) const;
 
   /**
    * Prepare string literal
@@ -156,6 +163,8 @@ private:
     {token_t::COLUMNS,     "COLUMNS"},
     {token_t::COLUMN,      "COLUMN"},
     {token_t::FROM,        "FROM"},
+    {token_t::JOIN,        "INNER JOIN"},
+    {token_t::ON,          "ON"},
     {token_t::WHERE,       "WHERE"},
     {token_t::AND,         "AND"},
     {token_t::OR,          "OR"},
@@ -178,6 +187,8 @@ private:
     {token_t::START_QUOTE, "\""},
     {token_t::END_QUOTE, "\""},
     {token_t::STRING_QUOTE, "'"},
+    {token_t::BEGIN_BINARY_DATA, "X'"},
+    {token_t::END_BINARY_DATA, "'"},
     {token_t::NONE, ""}
   };
 

include/matador/sql/entity.hpp

@@ -33,6 +33,8 @@ public:
   pointer get() { return obj_.get(); }
   const value_type* get() const { return obj_.get(); }
 
+  operator bool() const { return obj_.get() != nullptr; } // NOLINT(*-explicit-constructor)
+
 private:
   std::shared_ptr<value_type> obj_;
 };

include/matador/sql/entity_query_builder.hpp

@@ -0,0 +1,283 @@
+#ifndef QUERY_ENTITY_QUERY_BUILDER_HPP
+#define QUERY_ENTITY_QUERY_BUILDER_HPP
+
+#include "matador/sql/connection.hpp"
+#include "matador/sql/condition.hpp"
+#include "matador/sql/query_context.hpp"
+#include "matador/sql/query.hpp"
+#include "matador/sql/query_intermediates.hpp"
+#include "matador/sql/value.hpp"
+
+#include "matador/utils/result.hpp"
+
+#include <iostream>
+
+namespace matador::sql {
+
+struct join_columns
+{
+  std::string join_column;
+  std::string inverse_join_column;
+};
+
+class join_column_collector
+{
+public:
+  template<class Type>
+  join_columns collect()
+  {
+    join_columns_ = {};
+    Type obj;
+
+    matador::utils::access::process(*this, obj);
+
+    return join_columns_;
+  }
+  template < class V >
+  void on_primary_key(const char * /*id*/, V &, typename std::enable_if<std::is_integral<V>::value && !std::is_same<bool, V>::value>::type* = 0) {}
+  void on_primary_key(const char * /*id*/, std::string &, size_t) {}
+  void on_revision(const char * /*id*/, unsigned long long &/*rev*/) {}
+  template<typename Type>
+  void on_attribute(const char * /*id*/, Type &, const utils::field_attributes &/*attr*/ = utils::null_attributes) {}
+  template<class Pointer>
+  void on_belongs_to(const char * /*id*/, Pointer &obj, const utils::foreign_attributes &attr) {}
+  template<class Pointer>
+  void on_has_one(const char * /*id*/, Pointer &obj, const utils::foreign_attributes &attr) {}
+  template<class ContainerType>
+  void on_has_many(ContainerType &, const char *join_column, const utils::foreign_attributes &attr) {}
+  template<class ContainerType>
+  void on_has_many_to_many(const char * /*id*/, ContainerType &/*c*/, const char *join_column, const char *inverse_join_column, const utils::foreign_attributes &/*attr*/)
+  {
+    join_columns_.join_column = join_column;
+    join_columns_.inverse_join_column = inverse_join_column;
+  }
+  template<class ContainerType>
+  void on_has_many_to_many(const char * /*id*/, ContainerType &/*c*/, const utils::foreign_attributes &/*attr*/) {}
+
+private:
+  join_columns join_columns_;
+};
+
+struct entity_query_data {
+  std::string root_table_name;
+  std::string pk_column_;
+  std::vector<column> columns;
+  std::vector<join_data> joins;
+  std::unique_ptr<basic_condition> where_clause;
+};
+
+enum class query_build_error : std::uint8_t {
+  Ok = 0,
+  UnknownType,
+  MissingPrimaryKey,
+  UnexpectedError
+};
+
+class query_builder_exception : public std::exception
+{
+public:
+  explicit query_builder_exception(query_build_error error) : error_(error) {}
+
+  [[nodiscard]] query_build_error error() const { return error_; }
+
+private:
+  const query_build_error error_;
+};
+
+class entity_query_builder
+{
+public:
+  explicit entity_query_builder(const schema &scm)
+  : schema_(scm) {}
+
+  template<class EntityType, typename PrimaryKeyType>
+  utils::result<entity_query_data, query_build_error> build(const PrimaryKeyType &pk) {
+    const auto info = schema_.info<EntityType>();
+    if (!info) {
+      return utils::error(query_build_error::UnknownType);
+    }
+    pk_ = pk;
+    table_info_stack_.push(info.value());
+    entity_query_data_ = { info->name };
+    EntityType obj;
+    try {
+      matador::utils::access::process(*this, obj);
+
+      return {utils::ok(std::move(entity_query_data_))};
+    } catch (const query_builder_exception &ex) {
+      return {utils::error(ex.error())};
+    } catch (...) {
+      return {utils::error(query_build_error::UnexpectedError)};
+    }
+  }
+
+  template<class EntityType>
+  utils::result<entity_query_data, query_build_error> build() {
+    const auto info = schema_.info<EntityType>();
+    if (!info) {
+      return utils::error(query_build_error::UnknownType);
+    }
+    pk_ = nullptr;
+    table_info_stack_.push(info.value());
+    entity_query_data_ = { info->name };
+    EntityType obj;
+    try {
+      matador::utils::access::process(*this, obj);
+
+      return {utils::ok(std::move(entity_query_data_))};
+    } catch (const query_builder_exception &ex) {
+      return {utils::error(ex.error())};
+    } catch (...) {
+      return {utils::error(query_build_error::UnexpectedError)};
+    }
+  }
+
+  template < class V >
+  void on_primary_key(const char *id, V &, typename std::enable_if<std::is_integral<V>::value && !std::is_same<bool, V>::value>::type* = 0)
+  {
+    push(id);
+    if (!is_root_entity()) {
+      return;
+    }
+    if (pk_.is_null()) {
+      entity_query_data_.pk_column_ = id;
+    } else if (pk_.is_integer()) {
+      entity_query_data_.where_clause = make_condition(column{table_info_stack_.top().name, id, ""} == *pk_.as<V>());
+      entity_query_data_.pk_column_ = id;
+    }
+  }
+
+  void on_primary_key(const char *id, std::string &, size_t);
+  void on_revision(const char *id, unsigned long long &/*rev*/);
+
+  template<typename Type>
+  void on_attribute(const char *id, Type &, const utils::field_attributes &/*attr*/ = utils::null_attributes)
+  {
+    push(id);
+  }
+
+  template<class Pointer>
+  void on_belongs_to(const char *id, Pointer &obj, const utils::foreign_attributes &attr)
+  {
+    on_foreign_object(id, obj, attr);
+  }
+
+  template<class Pointer>
+  void on_has_one(const char *id, Pointer &obj, const utils::foreign_attributes &attr)
+  {
+    on_foreign_object(id, obj, attr);
+  }
+
+  template<class ContainerType>
+  void on_has_many(ContainerType &, const char *join_column, const utils::foreign_attributes &attr)
+  {
+    if (attr.fetch() == utils::fetch_type::EAGER) {
+      const auto info = schema_.info<typename ContainerType::value_type::value_type>();
+      if (!info) {
+        throw query_builder_exception{query_build_error::UnknownType};
+      }
+      table_info_stack_.push(info.value());
+      typename ContainerType::value_type::value_type obj;
+      matador::utils::access::process(*this , obj);
+      table_info_stack_.pop();
+
+      auto pk = info->prototype.primary_key();
+      if (!pk) {
+        throw query_builder_exception{query_build_error::MissingPrimaryKey};
+      }
+
+      append_join({table_info_stack_.top().name, table_info_stack_.top().prototype.primary_key()->name()}, {info->name, join_column});
+    }
+  }
+
+  template<class ContainerType>
+  void on_has_many_to_many(const char *id, ContainerType &c, const char *join_column, const char *inverse_join_column, const utils::foreign_attributes &attr)
+  {
+    if (attr.fetch() != utils::fetch_type::EAGER) {
+      return;
+    }
+    const auto info = schema_.info<typename ContainerType::value_type::value_type>();
+    if (!info) {
+      throw query_builder_exception{query_build_error::UnknownType};
+    }
+    table_info_stack_.push(info.value());
+    typename ContainerType::value_type::value_type obj;
+    matador::utils::access::process(*this , obj);
+    table_info_stack_.pop();
+
+    auto pk = info->prototype.primary_key();
+    if (!pk) {
+      throw query_builder_exception{query_build_error::MissingPrimaryKey};
+    }
+
+    append_join({table_info_stack_.top().name, table_info_stack_.top().prototype.primary_key()->name()}, {id, join_column});
+    append_join({id, inverse_join_column}, {info->name, pk->name()});
+  }
+
+  template<class ContainerType>
+  void on_has_many_to_many(const char *id, ContainerType &c, const utils::foreign_attributes &attr)
+  {
+    if (attr.fetch() != utils::fetch_type::EAGER) {
+      return;
+    }
+    const auto info = schema_.info<typename ContainerType::value_type::value_type>();
+    if (!info) {
+      throw query_builder_exception{query_build_error::UnknownType};
+    }
+    table_info_stack_.push(info.value());
+    typename ContainerType::value_type::value_type obj;
+    matador::utils::access::process(*this , obj);
+    table_info_stack_.pop();
+
+    auto pk = info->prototype.primary_key();
+    if (!pk) {
+      throw query_builder_exception{query_build_error::MissingPrimaryKey};
+    }
+
+    const auto join_columns = join_column_collector_.collect<typename ContainerType::value_type::value_type>();
+
+    append_join({table_info_stack_.top().name, table_info_stack_.top().prototype.primary_key()->name()}, {id, join_columns.inverse_join_column});
+    append_join({id, join_columns.join_column}, {info->name, pk->name()});
+  }
+
+private:
+  template<class Pointer>
+  void on_foreign_object(const char *id, Pointer &, const utils::foreign_attributes &attr);
+  void push(const std::string &column_name);
+  [[nodiscard]] bool is_root_entity() const;
+  void append_join(const column &left, const column &right);
+
+private:
+  value pk_;
+  std::stack<table_info> table_info_stack_;
+  const schema &schema_;
+  entity_query_data entity_query_data_;
+  int column_index{0};
+  join_column_collector join_column_collector_;
+};
+
+template<class Pointer>
+void entity_query_builder::on_foreign_object(const char *id, Pointer &, const utils::foreign_attributes &attr)
+{
+  if (attr.fetch() == utils::fetch_type::EAGER) {
+    const auto info = schema_.info<typename Pointer::value_type>();
+    if (!info) {
+      throw query_builder_exception{query_build_error::UnknownType};
+    }
+    table_info_stack_.push(info.value());
+    typename Pointer::value_type obj;
+    matador::utils::access::process(*this, obj);
+    table_info_stack_.pop();
+
+    auto pk = info->prototype.primary_key();
+    if (!pk) {
+      throw query_builder_exception{query_build_error::MissingPrimaryKey};
+    }
+    append_join({table_info_stack_.top().name, id}, {info->name, pk->name()});
+  } else {
+    push(id);
+  }
+}
+
+}
+#endif //QUERY_ENTITY_QUERY_BUILDER_HPP

include/matador/sql/field.hpp

@@ -0,0 +1,73 @@
+#ifndef QUERY_FIELD_HPP
+#define QUERY_FIELD_HPP
+
+#include "matador/sql/value.hpp"
+
+#include <optional>
+#include <string>
+
+namespace matador::sql {
+
+class field
+{
+public:
+  explicit field(std::string name);
+  template<typename Type>
+  field(std::string name, Type value, size_t size = 0, int index = -1)
+  : name_(std::move(name))
+  , index_(index)
+  , value_(value, size) {}
+  field(std::string name, data_type_t data_type, size_t size = 0, int index = -1);
+  field(const field &x) = default;
+  field& operator=(const field &x) = default;
+  field(field &&x) noexcept;
+  field& operator=(field &&x) noexcept;
+
+  template<typename Type>
+  field& operator=(Type value) {
+    value_ = std::move(value);
+
+    return *this;
+  }
+
+  [[nodiscard]] const std::string& name() const;
+  [[nodiscard]] size_t size() const;
+  [[nodiscard]] int index() const;
+
+  template<class Type>
+  std::optional<Type> as() const
+  {
+    return value_.as<Type>();
+  }
+
+  [[nodiscard]] std::string str() const;
+
+  [[nodiscard]] bool is_integer() const;
+  [[nodiscard]] bool is_floating_point() const;
+  [[nodiscard]] bool is_bool() const;
+  [[nodiscard]] bool is_string() const;
+  [[nodiscard]] bool is_varchar() const;
+  [[nodiscard]] bool is_blob() const;
+  [[nodiscard]] bool is_null() const;
+  [[nodiscard]] bool is_unknown() const;
+
+  friend std::ostream& operator<<(std::ostream &out, const field &col);
+
+private:
+  template<class Operator>
+  void process(Operator &op)
+  {
+    op.on_attribute(name_.c_str(), value_, value_.size());
+  }
+
+private:
+  friend class record;
+
+  std::string name_;
+  int index_{-1};
+
+  value value_;
+};
+
+}
+#endif //QUERY_FIELD_HPP

include/matador/sql/fk_value_extractor.hpp

@@ -31,13 +31,13 @@ public:
   void on_attribute(const char * /*id*/, Type &/*x*/, const utils::field_attributes &/*attr*/ = utils::null_attributes) {}
   void on_attribute(const char * /*id*/, char * /*x*/, const utils::field_attributes &/*attr*/ = utils::null_attributes) {}
   template<class Pointer>
-  void on_belongs_to(const char * /*id*/, Pointer &/*x*/, utils::cascade_type) {}
+  void on_belongs_to(const char * /*id*/, Pointer &/*x*/, const utils::foreign_attributes &/*attr*/) {}
   template<class Pointer>
-  void on_has_one(const char * /*id*/, Pointer &/*x*/, utils::cascade_type) {}
+  void on_has_one(const char * /*id*/, Pointer &/*x*/, const utils::foreign_attributes &/*attr*/) {}
   template<class ContainerType>
-  void on_has_many(const char *, ContainerType &, const char *, const char *, utils::cascade_type) {}
+  void on_has_many(const char *, ContainerType &, const char *, const char *, const utils::foreign_attributes &/*attr*/) {}
   template<class ContainerType>
-  void on_has_many(const char *, ContainerType &, utils::cascade_type) {}
+  void on_has_many(const char *, ContainerType &, const utils::foreign_attributes &/*attr*/) {}
 
 
 private:

include/matador/sql/has_many_to_many_relation.hpp

@@ -0,0 +1,38 @@
+#ifndef QUERY_HAS_MANY_TO_MANY_RELATION_HPP
+#define QUERY_HAS_MANY_TO_MANY_RELATION_HPP
+
+#include "matador/sql/entity.hpp"
+
+#include "matador/utils/access.hpp"
+#include "matador/utils/foreign_attributes.hpp"
+
+namespace matador::sql {
+
+template < class LocalType, class ForeignType >
+class has_many_to_many_relation
+{
+public:
+  has_many_to_many_relation() = default;
+  has_many_to_many_relation(std::string local_name, std::string remote_name)
+  : local_name_(std::move(local_name))
+  , remote_name_(std::move(remote_name)) {}
+
+  template<class Operator>
+  void process(Operator &op) {
+    namespace field = matador::utils::access;
+    field::belongs_to(op, local_name_.c_str(), local_, utils::default_foreign_attributes);
+    field::belongs_to(op, remote_name_.c_str(), remote_, utils::default_foreign_attributes);
+  }
+
+  entity<LocalType> local() const { return local_; }
+  entity<LocalType> remote() const { return remote_; }
+
+private:
+  std::string local_name_;
+  std::string remote_name_;
+  sql::entity<LocalType> local_;
+  sql::entity<ForeignType> remote_;
+};
+
+}
+#endif //QUERY_HAS_MANY_TO_MANY_RELATION_HPP

include/matador/sql/key_value_generator.hpp

@@ -40,19 +40,19 @@ public:
   }
 
   template<class Type, template < class ... > class Pointer>
-  void on_belongs_to(const char *id, Pointer<Type> &x, utils::cascade_type)
+  void on_belongs_to(const char *id, Pointer<Type> &x, const utils::foreign_attributes &/*attr*/)
   {
     result_.emplace_back(id, fk_value_extractor_.extract(*x));
   }
   template<class Type, template < class ... > class Pointer>
-  void on_has_one(const char *id, Pointer<Type> &x, utils::cascade_type)
+  void on_has_one(const char *id, Pointer<Type> &x, const utils::foreign_attributes &/*attr*/)
   {
     result_.emplace_back(id, fk_value_extractor_.extract(*x));
   }
   template<class ContainerType>
-  void on_has_many(const char *, ContainerType &, const char *, const char *, utils::cascade_type) {}
+  void on_has_many(const char *, ContainerType &, const char *, const char *, const utils::foreign_attributes &/*attr*/) {}
   template<class ContainerType>
-  void on_has_many(const char *, ContainerType &, utils::cascade_type) {}
+  void on_has_many(const char *, ContainerType &, const utils::foreign_attributes &/*attr*/) {}
 
 private:
   detail::fk_value_extractor fk_value_extractor_;

include/matador/sql/key_value_pair.hpp

@@ -2,13 +2,15 @@
 #define QUERY_KEY_VALUE_PAIR_HPP
 
 #include "matador/sql/any_type.hpp"
+#include "matador/sql/column.hpp"
 
 namespace matador::sql {
 
 class key_value_pair
 {
 public:
-  key_value_pair(const std::string &name, any_type value);
+  key_value_pair(const sql::column &col, any_type value);
+  key_value_pair(std::string name, any_type value);
   key_value_pair(const char *name, any_type value);
 
   [[nodiscard]] const std::string& name() const;

include/matador/sql/noop_connection.hpp

@@ -0,0 +1,26 @@
+#ifndef QUERY_NOOP_CONNECTION_HPP
+#define QUERY_NOOP_CONNECTION_HPP
+
+#include "matador/sql/connection_impl.hpp"
+
+namespace matador::sql {
+
+class noop_connection final : public connection_impl
+{
+public:
+  explicit noop_connection(const connection_info &info);
+
+  void open() override;
+  void close() override;
+  bool is_open() override;
+  size_t execute(const std::string &stmt) override;
+  std::unique_ptr<query_result_impl> fetch(const std::string &stmt) override;
+  std::unique_ptr<statement_impl> prepare(query_context context) override;
+  std::vector<sql::column_definition> describe(const std::string &table) override;
+  bool exists(const std::string &schema_name, const std::string &table_name) override;
+
+private:
+  bool is_open_{false};
+};
+}
+#endif //QUERY_NOOP_CONNECTION_HPP

include/matador/sql/object_parameter_binder.hpp

@@ -2,7 +2,7 @@
 #define QUERY_OBJECT_PARAMETER_BINDER_HPP
 
 #include "matador/sql/parameter_binder.hpp"
-#include "matador/sql/types.hpp"
+#include "matador/sql/data_type_traits.hpp"
 
 #include "matador/utils/access.hpp"
 #include "matador/utils/cascade_type.hpp"

include/matador/sql/parameter_binder.hpp

@@ -1,6 +1,8 @@
 #ifndef QUERY_PARAMETER_BINDER_HPP
 #define QUERY_PARAMETER_BINDER_HPP
 
+#include "matador/utils/types.hpp"
+
 #include <string>
 #include <cstring>
 
@@ -28,6 +30,7 @@ public:
   virtual void bind(size_t pos, const char *, size_t size) = 0;
   virtual void bind(size_t pos, const std::string&) = 0;
   virtual void bind(size_t pos, const std::string &x, size_t size) = 0;
+  virtual void bind(size_t pos, const utils::blob &) = 0;
 //  virtual void bind(size_t pos, const matador::time&) = 0;
 //  virtual void bind(size_t pos, const matador::date&) = 0;
 };

include/matador/sql/query.hpp

@@ -0,0 +1,32 @@
+#ifndef QUERY_QUERY_HPP
+#define QUERY_QUERY_HPP
+
+#include "matador/sql/query_intermediates.hpp"
+
+namespace matador::sql {
+
+class connection;
+
+class query
+{
+public:
+  explicit query(connection &db, const sql::schema &schema);
+  query(const query &) = delete;
+  query& operator=(const query &) = delete;
+
+  query_create_intermediate create();
+  query_drop_intermediate drop();
+  query_select_intermediate select(std::initializer_list<column> columns);
+  query_select_intermediate select(const std::vector<column>& columns);
+  query_select_intermediate select(std::vector<column> columns, std::initializer_list<column> additional_columns);
+  query_insert_intermediate insert();
+  query_update_intermediate update(const sql::table &table);
+  query_delete_intermediate remove();
+
+private:
+  connection &connection_;
+  const sql::schema &schema_;
+};
+
+}
+#endif //QUERY_QUERY_HPP

include/matador/sql/query_builder.hpp

@@ -2,7 +2,9 @@
 #define QUERY_QUERY_BUILDER_HPP
 
 #include "matador/sql/basic_condition.hpp"
+#include "matador/sql/column_definition.hpp"
 #include "matador/sql/column.hpp"
+#include "matador/sql/dialect.hpp"
 #include "matador/sql/key_value_pair.hpp"
 #include "matador/sql/query_context.hpp"
 #include "matador/sql/record.hpp"
@@ -10,12 +12,11 @@
 #include <string>
 #include <unordered_map>
 #include <unordered_set>
+#include <utility>
 #include <vector>
 
 namespace matador::sql {
 
-class dialect;
-
 namespace detail {
 struct any_type_to_string_visitor
 {
@@ -36,6 +37,7 @@ struct any_type_to_string_visitor
   void operator()(double &x) { to_string(x); }
   void operator()(const char *x) { to_string(x); }
   void operator()(std::string &x) { to_string(x); }
+  void operator()(utils::blob &x) { to_string(x); }
   void operator()(placeholder &x) { to_string(x); }
 
   template<typename Type>
@@ -45,6 +47,7 @@ struct any_type_to_string_visitor
   }
   void to_string(const char *val);
   void to_string(std::string &val);
+  void to_string(utils::blob &val);
   void to_string(placeholder &val);
 
   const dialect &d;
@@ -78,6 +81,8 @@ private:
     QUERY_DELETE,
     QUERY_SET,
     QUERY_FROM,
+    QUERY_JOIN,
+    QUERY_ON,
     QUERY_INTO,
     QUERY_WHERE,
     QUERY_VALUES,
@@ -99,6 +104,15 @@ private:
     REMOVE     /**< Remove query command */
   };
 
+  struct query_part
+  {
+    query_part(dialect::token_t t, std::string p)
+    : token(t), part(std::move(p)) {}
+
+    dialect::token_t token;
+    std::string part;
+  };
+
 public:
   explicit query_builder(const dialect &d);
 
@@ -110,15 +124,15 @@ public:
   query_builder& update(const std::string &table);
   query_builder& remove();
 
-  query_builder& table(const std::string &table, std::initializer_list<column> columns);
+  query_builder& table(const std::string &table, std::initializer_list<column_definition> columns);
-  query_builder& table(const std::string &table, const std::vector<column> &columns);
+  query_builder& table(const std::string &table, const std::vector<column_definition> &columns);
   query_builder& table(const std::string &table);
-  query_builder& into(const std::string &table, std::initializer_list<std::string> column_names);
+  query_builder& into(const std::string &table, std::initializer_list<column> column_names);
-  query_builder& into(const std::string &table, const std::vector<std::string> &column_names);
+  query_builder& into(const std::string &table, const std::vector<column> &column_names);
   query_builder& values(std::initializer_list<any_type> values);
   query_builder& values(const std::vector<any_type> &values);
   query_builder& from(const std::string &table, const std::string &as = "");
-  query_builder& join(const std::string &table, join_type_t);
+  query_builder& join(const std::string &table, join_type_t, const std::string &as = "");
   query_builder& on(const std::string &column, const std::string &join_column);
   query_builder& set(std::initializer_list<key_value_pair> key_values);
   query_builder& set(const std::vector<key_value_pair> &key_values);
@@ -142,7 +156,7 @@ private:
   command_t command_{command_t::UNKNOWN};
   state_t state_{state_t::QUERY_INIT};
 
-  std::vector<std::string> query_parts_;
+  std::vector<query_part> query_parts_;
 
   detail::any_type_to_string_visitor value_to_string_;
 

include/matador/sql/query_compiler.hpp

@@ -0,0 +1,59 @@
+#ifndef QUERY_QUERY_COMPILER_HPP
+#define QUERY_QUERY_COMPILER_HPP
+
+#include "matador/sql/query_part_visitor.hpp"
+#include "matador/sql/query_parts.hpp"
+#include "matador/sql/query_context.hpp"
+
+#include <typeindex>
+#include <string>
+
+namespace matador::sql {
+
+class dialect;
+
+struct query_data;
+
+class query_compiler : public query_part_visitor
+{
+public:
+  explicit query_compiler(const sql::dialect& d);
+
+  query_context compile(const query_data *data);
+
+private:
+  void visit(query_select_part &select_part) override;
+  void visit(query_from_part &from_part) override;
+  void visit(query_join_part &join_part) override;
+  void visit(query_on_part &on_part) override;
+  void visit(query_where_part &where_part) override;
+  void visit(query_group_by_part &group_by_part) override;
+  void visit(query_order_by_part &order_by_part) override;
+  void visit(query_order_by_asc_part &order_by_asc_part) override;
+  void visit(query_order_by_desc_part &order_by_desc_part) override;
+  void visit(query_offset_part &offset_part) override;
+  void visit(query_limit_part &limit_part) override;
+  void visit(query_insert_part &insert_part) override;
+  void visit(query_into_part &into_part) override;
+  void visit(query_values_part &values_part) override;
+
+  void visit(query_update_part &update_part) override;
+  void visit(query_set_part &set_part) override;
+
+  void visit(query_delete_part &delete_part) override;
+  void visit(query_delete_from_part &delete_from_part) override;
+
+  void visit(query_create_part &create_part) override;
+  void visit(query_create_table_part &create_table_part) override;
+
+  void visit(query_drop_part &drop_part) override;
+  void visit(query_drop_table_part &drop_table_part) override;
+
+private:
+  const sql::dialect &dialect_;
+  query_context query_;
+};
+
+}
+
+#endif //QUERY_QUERY_COMPILER_HPP

include/matador/sql/query_context.hpp

@@ -1,7 +1,8 @@
 #ifndef QUERY_QUERY_CONTEXT_HPP
 #define QUERY_QUERY_CONTEXT_HPP
 
-#include "matador/sql/record.hpp"
+#include "matador/sql/column_definition.hpp"
+#include "matador/sql/table.hpp"
 
 namespace matador::sql {
 
@@ -9,8 +10,8 @@ struct query_context
 {
   std::string sql;
   std::string command_name;
-  std::string table_name;
+  sql::table table{""};
-  record prototype;
+  std::vector<column_definition> prototype;
   std::vector<std::string> result_vars;
   std::vector<std::string> bind_vars;
 };

include/matador/sql/query_data.hpp

@@ -0,0 +1,23 @@
+#ifndef QUERY_QUERY_DATA_HPP
+#define QUERY_QUERY_DATA_HPP
+
+#include "matador/sql/query_part.hpp"
+#include "matador/sql/table.hpp"
+
+#include <memory>
+#include <vector>
+
+namespace matador::sql {
+
+class query_part;
+
+struct query_data
+{
+//  SqlCommands command;
+  std::vector<std::unique_ptr<query_part>> parts;
+  std::vector<column_definition> columns;
+};
+
+}
+
+#endif //QUERY_QUERY_DATA_HPP

include/matador/sql/query_helper.hpp

@@ -0,0 +1,24 @@
+#ifndef QUERY_QUERY_HELPER_HPP
+#define QUERY_QUERY_HELPER_HPP
+
+#include "matador/utils/macro_map.hpp"
+
+#include "matador/sql/table.hpp"
+#include "matador/sql/column.hpp"
+
+#include <string>
+#include <ostream>
+
+#define FIELD(x) const sql::column x{*this, #x, ""};
+
+#define QUERY_HELPER(C, ...) \
+namespace matador::qh {     \
+namespace internal {                      \
+struct C##_query : sql::table {           \
+C##_query() : table(#C) {}                            \
+MAP(FIELD, __VA_ARGS__) \
+}; }                     \
+static const internal:: C##_query C;  \
+}
+
+#endif //QUERY_QUERY_HELPER_HPP

include/matador/sql/query_intermediates.hpp

@@ -1,17 +1,17 @@
 #ifndef QUERY_QUERY_INTERMEDIATES_HPP
 #define QUERY_QUERY_INTERMEDIATES_HPP
 
-#include "matador/sql/column.hpp"
+#include "matador/sql/column_definition.hpp"
+#include "matador/sql/column_definition_generator.hpp"
 #include "matador/sql/column_generator.hpp"
-#include "matador/sql/column_name_generator.hpp"
 #include "matador/sql/key_value_generator.hpp"
 #include "matador/sql/key_value_pair.hpp"
 #include "matador/sql/placeholder_generator.hpp"
-#include "matador/sql/query_builder.hpp"
 #include "matador/sql/query_result.hpp"
+#include "matador/sql/query_data.hpp"
 #include "matador/sql/record.hpp"
 #include "matador/sql/statement.hpp"
-#include "matador/sql/table_repository.hpp"
+#include "matador/sql/schema.hpp"
 #include "matador/sql/value_extractor.hpp"
 
 #include <string>
@@ -19,28 +19,38 @@
 namespace matador::sql {
 
 class basic_condition;
-class session;
+class connection;
 
-class query_intermediate
+class basic_query_intermediate
 {
 public:
-  query_intermediate(session &db, query_builder &query);
+  explicit basic_query_intermediate(connection &db, const sql::schema &schema);
 
 protected:
-  session &session_;
+  connection &connection_;
-  query_builder &builder_;
+  const sql::schema &schema_;
 };
 
-class query_execute_finish : public query_intermediate
+class query_intermediate : public basic_query_intermediate
+{
+public:
+  query_intermediate(connection &db, const sql::schema &schema, const std::shared_ptr<query_data> &data);
+
+protected:
+  std::shared_ptr<query_data> data_;
+};
+
+class query_execute : public query_intermediate
 {
 public:
   using query_intermediate::query_intermediate;
 
   size_t execute();
   statement prepare();
+  [[nodiscard]] query_context build() const;
 };
 
-class query_select_finish : public query_intermediate
+class query_select : public query_intermediate
 {
 protected:
   using query_intermediate::query_intermediate;
@@ -51,52 +61,73 @@ public:
   {
     return query_result<Type>(fetch());
   }
-
   query_result<record> fetch_all();
-  record fetch_one();
+
-  template<typename Type>
+  template < class Type >
-  Type fetch_value()
+  std::unique_ptr<Type> fetch_one()
   {
-    return fetch_one().at(0).as<Type>();
+    auto result = query_result<Type>(fetch());
+    auto first = result.begin();
+    if (first == result.end()) {
+      return nullptr;
+    }
+
+    return std::unique_ptr<Type>{first.release()};
+  }
+  std::optional<record> fetch_one();
+
+  template<typename Type>
+  std::optional<Type> fetch_value()
+  {
+    const auto result = fetch_one();
+    if (result.has_value()) {
+      return result.value().at(0).as<Type>().value();
+    }
+    return std::nullopt;
   }
 
   statement prepare();
 
+  [[nodiscard]] query_context build() const;
+
 private:
   std::unique_ptr<query_result_impl> fetch();
 };
 
-class query_limit_intermediate : public query_select_finish
+class query_offset_intermediate;
+
+class query_limit_intermediate : public query_select
 {
 public:
-  using query_select_finish::query_select_finish;
+  using query_select::query_select;
+
+  query_offset_intermediate offset(size_t offset);
 };
 
-class query_offset_intermediate : public query_intermediate
+class query_offset_intermediate : public query_select
 {
 public:
-  using query_intermediate::query_intermediate;
+  using query_select::query_select;
 
   query_limit_intermediate limit(size_t limit);
 };
 
-class query_order_direction_intermediate : public query_select_finish
+class query_order_direction_intermediate : public query_select
 {
 public:
-  using query_select_finish::query_select_finish;
+  using query_select::query_select;
 
-  query_offset_intermediate offset(size_t offset);
   query_limit_intermediate limit(size_t limit);
 };
 
 class query_order_by_intermediate;
 
-class query_group_by_intermediate : public query_select_finish
+class query_group_by_intermediate : public query_select
 {
 public:
-  using query_select_finish::query_select_finish;
+  using query_select::query_select;
 
-  query_order_by_intermediate order_by(const std::string &name);
+  query_order_by_intermediate order_by(const column &col);
 };
 
 class query_order_by_intermediate : public query_intermediate
@@ -108,41 +139,84 @@ public:
   query_order_direction_intermediate desc();
 };
 
-class query_where_intermediate : public query_select_finish
+class query_where_intermediate : public query_select
 {
 public:
-  using query_select_finish::query_select_finish;
+  using query_select::query_select;
 
-  query_group_by_intermediate group_by(const std::string &name);
+  query_group_by_intermediate group_by(const column &col);
-  query_order_by_intermediate order_by(const std::string &name);
+  query_order_by_intermediate order_by(const column &col);
 };
 
-class query_from_intermediate : public query_select_finish
+class query_join_intermediate;
-{
-public:
-  using query_select_finish::query_select_finish;
 
-  query_where_intermediate where(const basic_condition &cond);
+struct join_data
-  query_group_by_intermediate group_by(const std::string &name);
+{
-  query_order_by_intermediate order_by(const std::string &name);
+  table join_table;
+  std::unique_ptr<basic_condition> condition;
 };
 
-class query_start_intermediate
+class query_from_intermediate : public query_select
 {
 public:
-  explicit query_start_intermediate(session &s);
+  using query_select::query_select;
+
+  query_join_intermediate join_left(const table &t);
+  query_from_intermediate join_left(join_data &data);
+  query_from_intermediate join_left(std::vector<join_data> &data_vector);
+
+  template<class Condition>
+  query_where_intermediate where(const Condition &cond)
+  {
+    return where_clause(std::make_unique<Condition>(std::move(cond)));
+  }
+  query_where_intermediate where(std::unique_ptr<basic_condition> &&cond)
+  {
+    return where_clause(std::move(cond));
+  }
+  query_group_by_intermediate group_by(const column &col);
+  query_order_by_intermediate order_by(const column &col);
+
+private:
+  query_where_intermediate where_clause(std::unique_ptr<basic_condition> &&cond);
+};
+
+using query_on_intermediate = query_from_intermediate;
+
+class query_join_intermediate : public query_intermediate
+{
+public:
+  using query_intermediate::query_intermediate;
+
+  template<class Condition>
+  query_on_intermediate on(const Condition &cond)
+  {
+    return on_clause(std::make_unique<Condition>(std::move(cond)));
+  }
+  query_on_intermediate on(std::unique_ptr<basic_condition> &&cond)
+  {
+    return on_clause(std::move(cond));
+  }
+
+private:
+  query_on_intermediate on_clause(std::unique_ptr<basic_condition> &&cond);
+};
+
+class query_start_intermediate : public basic_query_intermediate
+{
+public:
+  explicit query_start_intermediate(connection &db, const sql::schema &schema);
 
 protected:
-  session &session_;
+  std::shared_ptr<query_data> data_ { std::make_shared<query_data>() };
-  query_builder builder_;
 };
 
 class query_select_intermediate : public query_start_intermediate
 {
 public:
-  query_select_intermediate(session &s, const std::vector<column>& columns);
+  query_select_intermediate(connection &db, const sql::schema &schema, const std::vector<column>& columns);
 
-  query_from_intermediate from(const std::string &table, const std::string &as = "");
+  query_from_intermediate from(const table& t);
 };
 
 template < class Type >
@@ -159,107 +233,111 @@ class query_into_intermediate : public query_intermediate
 public:
   using query_intermediate::query_intermediate;
 
-  query_execute_finish values(std::initializer_list<any_type> values);
+  query_execute values(std::initializer_list<any_type> values);
+  query_execute values(std::vector<any_type> &&values);
   template<class Type>
-  query_execute_finish values()
+  query_execute values()
   {
     Type obj;
-    return {session_, builder_.values(as_placeholder(obj))};
+    return values(std::move(as_placeholder(obj)));
   }
   template<class Type>
-  query_execute_finish values(const Type &obj)
+  query_execute values(const Type &obj)
   {
-    return {session_, builder_.values(value_extractor::extract(obj))};
+    return values(std::move(value_extractor::extract(obj)));
   }
 };
 
-class query_create_intermediate : query_start_intermediate
+class query_create_intermediate : public query_start_intermediate
 {
 public:
-  query_create_intermediate(session &s, table_repository &repo);
+  explicit query_create_intermediate(connection &db, const sql::schema &schema);
 
-  query_execute_finish table(const std::string &table, std::initializer_list<column> columns);
+  query_execute table(const sql::table &table, std::initializer_list<column_definition> columns);
+  query_execute table(const sql::table &table, const std::vector<column_definition> &columns);
   template<class Type>
-  query_execute_finish table(const std::string &table_name)
+  query_execute table(const sql::table &table)
   {
-    const auto &info = repository_.attach<Type>(table_name);
+    return this->table(table, column_definition_generator::generate<Type>(schema_));
-    return {session_, builder_.table(table_name, info.prototype.columns())};
   }
-
-private:
-  table_repository &repository_;
 };
 
 class query_drop_intermediate : query_start_intermediate
 {
 public:
-  explicit query_drop_intermediate(session &s);
+  explicit query_drop_intermediate(connection &db, const sql::schema &schema);
 
-  query_execute_finish table(const std::string &table);
+  query_execute table(const sql::table &table);
 };
 
 class query_insert_intermediate : public query_start_intermediate
 {
 public:
-  explicit query_insert_intermediate(session &s);
+  explicit query_insert_intermediate(connection &db, const sql::schema &schema);
 
-  query_into_intermediate into(const std::string &table, std::initializer_list<std::string> column_names);
+  query_into_intermediate into(const sql::table &table, std::initializer_list<column> column_names);
-  template<class Type>
+  query_into_intermediate into(const sql::table &table, std::vector<column> &&column_names);
-  query_into_intermediate into(const std::string &table)
+  query_into_intermediate into(const sql::table &table);
-  {
-    return {session_, builder_.into(table, column_name_generator::generate<Type>())};
-  }
-  template<class Type>
-  query_execute_finish into(const std::string &table, const Type &obj)
-  {
-    return {session_, builder_.into(table, column_name_generator::generate<Type>())
-                         .values(value_extractor::extract(obj))};
-  }
 };
 
-class query_execute_where_intermediate : public query_execute_finish
+class query_execute_where_intermediate : public query_execute
 {
 public:
-  using query_execute_finish::query_execute_finish;
+  using query_execute::query_execute;
 
-  query_execute_finish limit(int limit);
+  query_order_by_intermediate order_by(const column &col);
 };
 
-class query_set_intermediate : public query_execute_finish
+class query_set_intermediate : public query_execute
 {
 public:
-  using query_execute_finish::query_execute_finish;
+  using query_execute::query_execute;
 
-  query_execute_where_intermediate where(const basic_condition &cond);
+  template<class Condition>
+  query_execute_where_intermediate where(const Condition &cond)
+  {
+    return where_clause(std::make_unique<Condition>(std::move(cond)));
+  }
+
+private:
+  query_execute_where_intermediate where_clause(std::unique_ptr<basic_condition> &&cond);
 };
 
 class query_update_intermediate : public query_start_intermediate
 {
 public:
-  query_update_intermediate(session &s, const std::string& table_name);
+  query_update_intermediate(connection &db, const sql::schema &schema, const sql::table& table);
 
   query_set_intermediate set(std::initializer_list<key_value_pair> columns);
+  query_set_intermediate set(std::vector<key_value_pair> &&columns);
   template<class Type>
   query_set_intermediate set(const Type &obj)
   {
-    return {session_, builder_.set(key_value_generator::generate(obj))};
+    return set(key_value_generator::generate(obj));
   }
 };
 
-class query_delete_from_intermediate : public query_execute_finish
+class query_delete_from_intermediate : public query_execute
 {
 public:
-  using query_execute_finish::query_execute_finish;
+  using query_execute::query_execute;
 
-  query_execute_where_intermediate where(const basic_condition &cond);
+  template<class Condition>
+  query_execute_where_intermediate where(const Condition &cond)
+  {
+    return where_clause(std::make_unique<Condition>(std::move(cond)));
+  }
+
+private:
+  query_execute_where_intermediate where_clause(std::unique_ptr<basic_condition> &&cond);
 };
 
 class query_delete_intermediate : public query_start_intermediate
 {
 public:
-  explicit query_delete_intermediate(session &s);
+  explicit query_delete_intermediate(connection &db, const sql::schema &schema);
 
-  query_delete_from_intermediate from(const std::string &table);
+  query_delete_from_intermediate from(const sql::table &table);
 };
 
 }

include/matador/sql/query_part.hpp

@@ -0,0 +1,26 @@
+#ifndef QUERY_QUERY_PART_HPP
+#define QUERY_QUERY_PART_HPP
+
+#include "matador/sql/dialect.hpp"
+
+namespace matador::sql {
+
+class query_part_visitor;
+
+class query_part
+{
+protected:
+  explicit query_part(sql::dialect::token_t token);
+
+public:
+  virtual ~query_part() = default;
+  virtual void accept(query_part_visitor &visitor) = 0;
+
+  [[nodiscard]] dialect::token_t token() const;
+
+protected:
+  sql::dialect::token_t token_;
+};
+
+}
+#endif //QUERY_QUERY_PART_HPP

include/matador/sql/query_part_visitor.hpp

@@ -0,0 +1,65 @@
+#ifndef QUERY_QUERY_PART_VISITOR_HPP
+#define QUERY_QUERY_PART_VISITOR_HPP
+
+namespace matador::sql {
+
+class query_select_part;
+class query_from_part;
+class query_join_part;
+class query_on_part;
+class query_where_part;
+class query_group_by_part;
+class query_order_by_part;
+class query_order_by_asc_part;
+class query_order_by_desc_part;
+class query_offset_part;
+class query_limit_part;
+class query_insert_part;
+class query_into_part;
+class query_values_part;
+class query_update_part;
+class query_set_part;
+class query_delete_part;
+class query_delete_from_part;
+class query_create_part;
+class query_create_table_part;
+class query_drop_part;
+class query_drop_table_part;
+
+class query_part_visitor
+{
+public:
+  virtual ~query_part_visitor() = default;
+
+  virtual void visit(query_select_part &select_part) = 0;
+  virtual void visit(query_from_part &from_part) = 0;
+  virtual void visit(query_join_part &join_part) = 0;
+  virtual void visit(query_on_part &on_part) = 0;
+  virtual void visit(query_where_part &where_part) = 0;
+  virtual void visit(query_group_by_part &group_by_part) = 0;
+  virtual void visit(query_order_by_part &order_by_part) = 0;
+  virtual void visit(query_order_by_asc_part &order_by_asc_part) = 0;
+  virtual void visit(query_order_by_desc_part &order_by_desc_part) = 0;
+  virtual void visit(query_offset_part &offset_part) = 0;
+  virtual void visit(query_limit_part &limit_part) = 0;
+
+  virtual void visit(query_insert_part &insert_part) = 0;
+  virtual void visit(query_into_part &into_part) = 0;
+  virtual void visit(query_values_part &values_part) = 0;
+
+  virtual void visit(query_update_part &update_part) = 0;
+  virtual void visit(query_set_part &set_part) = 0;
+
+  virtual void visit(query_delete_part &delete_part) = 0;
+  virtual void visit(query_delete_from_part &delete_from_part) = 0;
+
+  virtual void visit(query_create_part &create_part) = 0;
+  virtual void visit(query_create_table_part &create_table_part) = 0;
+
+  virtual void visit(query_drop_part &drop_part) = 0;
+  virtual void visit(query_drop_table_part &drop_table_part) = 0;
+};
+
+}
+
+#endif //QUERY_QUERY_PART_VISITOR_HPP

include/matador/sql/query_parts.hpp

@@ -0,0 +1,324 @@
+#ifndef QUERY_QUERY_PARTS_HPP
+#define QUERY_QUERY_PARTS_HPP
+
+#include "matador/sql/basic_condition.hpp"
+#include "matador/sql/query_part_visitor.hpp"
+#include "matador/sql/column.hpp"
+#include "matador/sql/column_definition.hpp"
+#include "matador/sql/key_value_pair.hpp"
+#include "matador/sql/query_part.hpp"
+#include "matador/sql/table.hpp"
+
+#include <memory>
+
+namespace matador::sql {
+
+class basic_condition;
+
+/**
+ * Represents the SQL SELECT part
+ */
+class query_select_part : public query_part
+{
+public:
+  explicit query_select_part(std::vector<column> columns);
+  void accept(query_part_visitor &visitor) override;
+
+  [[nodiscard]] const std::vector<column>& columns() const;
+
+private:
+  std::vector<column> columns_;
+};
+
+/**
+ * Represents the SQL FROM part
+ */
+class query_from_part : public query_part
+{
+public:
+  explicit query_from_part(sql::table t);
+
+  [[nodiscard]] const sql::table& table() const;
+
+private:
+  void accept(query_part_visitor &visitor) override;
+
+private:
+  sql::table table_;
+};
+
+class query_join_part : public query_part
+{
+public:
+  explicit query_join_part(sql::table t);
+
+  [[nodiscard]] const sql::table& table() const;
+
+private:
+  void accept(query_part_visitor &visitor) override;
+
+private:
+  sql::table table_;
+};
+
+class query_on_part : public query_part
+{
+public:
+  template < class Condition >
+  explicit query_on_part(const Condition &cond)
+    : query_part(dialect::token_t::ON)
+    , condition_(new Condition(cond)) {}
+  explicit query_on_part(std::unique_ptr<basic_condition> &&cond);
+
+  [[nodiscard]] const basic_condition& condition() const;
+
+private:
+  void accept(query_part_visitor &visitor) override;
+
+private:
+  std::unique_ptr<basic_condition> condition_;
+};
+
+class query_where_part : public query_part
+{
+public:
+  template < class Condition >
+  explicit query_where_part(const Condition &cond)
+  : query_part(dialect::token_t::WHERE)
+  , condition_(new Condition(cond)) {}
+  explicit query_where_part(std::unique_ptr<basic_condition> &&cond);
+
+  [[nodiscard]] const basic_condition& condition() const;
+
+private:
+  void accept(query_part_visitor &visitor) override;
+
+private:
+  std::unique_ptr<basic_condition> condition_;
+};
+
+class query_table_name_part : public query_part
+{
+protected:
+  explicit query_table_name_part(sql::dialect::token_t token, std::string table_name);
+
+protected:
+  std::string table_name_;
+};
+
+class query_group_by_part : public query_part
+{
+public:
+  explicit query_group_by_part(sql::column  col);
+
+  [[nodiscard]] const sql::column& column() const;
+
+private:
+  void accept(query_part_visitor &visitor) override;
+
+private:
+  sql::column column_;
+};
+
+class query_order_by_part : public query_part
+{
+public:
+  explicit query_order_by_part(sql::column  col);
+
+  [[nodiscard]] const sql::column& column() const;
+
+private:
+  void accept(query_part_visitor &visitor) override;
+
+private:
+  sql::column column_;
+};
+
+class query_order_by_asc_part : public query_part
+{
+public:
+  query_order_by_asc_part();
+
+private:
+  void accept(query_part_visitor &visitor) override;
+};
+
+class query_order_by_desc_part : public query_part
+{
+public:
+  query_order_by_desc_part();
+
+private:
+  void accept(query_part_visitor &visitor) override;
+};
+
+class query_offset_part : public query_part
+{
+public:
+  explicit query_offset_part(size_t offset);
+
+  [[nodiscard]] size_t offset() const;
+
+private:
+  void accept(query_part_visitor &visitor) override;
+
+private:
+  size_t offset_;
+};
+
+class query_limit_part : public query_part
+{
+public:
+  explicit query_limit_part(size_t limit);
+
+  [[nodiscard]] size_t limit() const;
+
+private:
+  void accept(query_part_visitor &visitor) override;
+
+private:
+  size_t limit_;
+};
+
+class query_insert_part : public query_part
+{
+public:
+  query_insert_part();
+
+private:
+  void accept(query_part_visitor &visitor) override;
+};
+
+class query_into_part : public query_part
+{
+public:
+  query_into_part(sql::table t, std::vector<sql::column> columns);
+
+  [[nodiscard]] const sql::table& table() const;
+  [[nodiscard]] const std::vector<column>& columns() const;
+
+private:
+  void accept(query_part_visitor &visitor) override;
+
+private:
+  sql::table table_;
+  std::vector<column> columns_;
+};
+/**
+ * Represents the SQL VALUES part
+ */
+class query_values_part : public query_part
+{
+public:
+  explicit query_values_part(std::vector<any_type> &&values);
+
+  [[nodiscard]] const std::vector<any_type>& values() const;
+
+private:
+  void accept(query_part_visitor &visitor) override;
+
+private:
+  std::vector<any_type> values_;
+};
+
+class query_update_part : public query_part
+{
+public:
+  explicit query_update_part(sql::table table);
+
+  [[nodiscard]] const sql::table& table() const;
+
+private:
+  void accept(query_part_visitor &visitor) override;
+
+private:
+  sql::table table_;
+};
+
+class query_set_part : public query_part
+{
+public:
+  explicit query_set_part(const std::vector<sql::key_value_pair>& key_value_pairs);
+
+  [[nodiscard]] const std::vector<sql::key_value_pair>& key_values() const;
+
+private:
+  void accept(query_part_visitor &visitor) override;
+
+private:
+  std::vector<sql::key_value_pair> key_value_pairs_;
+};
+
+class query_delete_part : public query_part
+{
+public:
+  query_delete_part();
+
+private:
+  void accept(query_part_visitor &visitor) override;
+};
+
+class query_delete_from_part : public query_part
+{
+public:
+  query_delete_from_part(sql::table table);
+
+  [[nodiscard]] const sql::table& table() const;
+
+private:
+  void accept(query_part_visitor &visitor) override;
+
+private:
+  sql::table table_;
+};
+
+class query_create_part : public query_part
+{
+public:
+  query_create_part();
+
+private:
+  void accept(query_part_visitor &visitor) override;
+};
+
+class query_create_table_part : public query_part
+{
+public:
+  query_create_table_part(sql::table table, std::vector<sql::column_definition> columns);
+
+  [[nodiscard]] const sql::table& table() const;
+  [[nodiscard]] const std::vector<sql::column_definition>& columns() const;
+
+private:
+  void accept(query_part_visitor &visitor) override;
+
+private:
+  sql::table table_;
+  std::vector<sql::column_definition> columns_;
+};
+
+class query_drop_part : public query_part
+{
+public:
+  query_drop_part();
+
+private:
+  void accept(query_part_visitor &visitor) override;
+};
+
+class query_drop_table_part : public query_part
+{
+public:
+  explicit query_drop_table_part(sql::table table);
+
+  [[nodiscard]] const sql::table& table() const;
+
+private:
+  void accept(query_part_visitor &visitor) override;
+
+private:
+  sql::table table_;
+};
+
+}
+#endif //QUERY_QUERY_PARTS_HPP

include/matador/sql/query_result.hpp

@@ -1,14 +1,15 @@
 #ifndef QUERY_QUERY_RESULT_HPP
 #define QUERY_QUERY_RESULT_HPP
 
-#include <functional>
-
 #include "matador/sql/query_result_impl.hpp"
 
+#include <functional>
 #include <memory>
 
 namespace matador::sql {
 
+class record;
+
 template < typename Type >
 class query_result;
 
@@ -108,13 +109,13 @@ private:
 namespace detail {
 
 template < typename Type >
-Type* create_prototype(const record &/*prototype*/)
+Type* create_prototype(const std::vector<column_definition> &/*prototype*/)
 {
   return new Type{};
 }
 
 template <>
-record* create_prototype<record>(const record &prototype);
+record* create_prototype<record>(const std::vector<column_definition> &prototype);
 
 }
 
@@ -129,7 +130,7 @@ public:
   explicit query_result(std::unique_ptr<query_result_impl> impl)
   : impl_(std::move(impl)) {}
 
-  query_result(std::unique_ptr<query_result_impl> impl, record record_prototype)
+  query_result(std::unique_ptr<query_result_impl> impl, std::vector<column_definition> record_prototype)
   : record_prototype_(std::move(record_prototype))
   , impl_(std::move(impl)) {}
 
@@ -152,7 +153,7 @@ private:
   }
 
 private:
-  record record_prototype_;
+  std::vector<column_definition> record_prototype_;
   std::unique_ptr<query_result_impl> impl_;
 };
 

include/matador/sql/query_result_impl.hpp

@@ -3,17 +3,20 @@
 
 #include "matador/utils/access.hpp"
 #include "matador/utils/field_attributes.hpp"
+#include "matador/utils/foreign_attributes.hpp"
 
 #include "matador/sql/any_type.hpp"
 #include "matador/sql/query_result_reader.hpp"
-#include "matador/sql/record.hpp"
+#include "matador/sql/column_definition.hpp"
-#include "matador/sql/types.hpp"
+#include "matador/sql/data_type_traits.hpp"
 
 #include <memory>
 #include <string>
 
 namespace matador::sql {
 
+class value;
+
 namespace detail {
 class pk_reader
 {
@@ -35,14 +38,16 @@ public:
   template < class Type >
   void on_attribute(const char * /*id*/, Type &/*x*/, const utils::field_attributes &/*attr*/ = utils::null_attributes) {}
   template < class Pointer >
-  void on_belongs_to(const char * /*id*/, Pointer &/*x*/, utils::cascade_type) {}
+  void on_belongs_to(const char * /*id*/, Pointer &/*x*/, const utils::foreign_attributes &/*attr*/) {}
   template < class Pointer >
-  void on_has_one(const char * /*id*/, Pointer &/*x*/, utils::cascade_type) {}
+  void on_has_one(const char * /*id*/, Pointer &/*x*/, const utils::foreign_attributes &/*attr*/) {}
 
   template<class ContainerType>
-  void on_has_many(const char *, ContainerType &, const char *, const char *, utils::cascade_type) {}
+  void on_has_many(ContainerType &, const char *, const utils::foreign_attributes &/*attr*/) {}
   template<class ContainerType>
-  void on_has_many(const char *, ContainerType &, utils::cascade_type) {}
+  void on_has_many_to_many(const char *id, ContainerType &c, const char *join_column, const char *inverse_join_column, const utils::foreign_attributes &/*attr*/) {}
+  template<class ContainerType>
+  void on_has_many_to_many(const char *id, ContainerType &c, const utils::foreign_attributes &/*attr*/) {}
 
 private:
   size_t column_index_{};
@@ -54,7 +59,7 @@ private:
 class query_result_impl
 {
 public:
-  query_result_impl(std::unique_ptr<query_result_reader> &&reader, record prototype);
+  query_result_impl(std::unique_ptr<query_result_reader> &&reader, std::vector<column_definition> prototype);
 
   template<typename ValueType>
   void on_primary_key(const char *id, ValueType &value, typename std::enable_if<std::is_integral<ValueType>::value && !std::is_same<bool, ValueType>::value>::type* = 0)
@@ -71,29 +76,37 @@ public:
   }
   void on_attribute(const char *id, char *value, const utils::field_attributes &attr = utils::null_attributes);
   void on_attribute(const char *id, std::string &value, const utils::field_attributes &attr = utils::null_attributes);
-  void on_attribute(const char *id, any_type &value, data_type_t type, const utils::field_attributes &attr = utils::null_attributes);
+  void on_attribute(const char *id, value &val, const utils::field_attributes &attr = utils::null_attributes);
 
   template < class Pointer >
-  void on_belongs_to(const char * /*id*/, Pointer &x, utils::cascade_type)
+  void on_belongs_to(const char * /*id*/, Pointer &x, const utils::foreign_attributes &attr)
   {
     if (!x.get()) {
       x.reset(new typename Pointer::value_type);
     }
+    if (attr.fetch() == utils::fetch_type::LAZY) {
       pk_reader_.read(*x, column_index_++);
+    } else {
+      utils::access::process(*this, *x);
+    }
   }
   template < class Pointer >
-  void on_has_one(const char * /*id*/, Pointer &x, utils::cascade_type)
+  void on_has_one(const char * /*id*/, Pointer &x, const utils::foreign_attributes &attr)
   {
     if (!x.get()) {
       x.reset(new typename Pointer::value_type);
     }
+    if (attr.fetch() == utils::fetch_type::LAZY) {
       pk_reader_.read(*x, column_index_++);
+    } else {
+      utils::access::process(*this, *x);
+    }
   }
 
   template<class ContainerType>
-  void on_has_many(const char *, ContainerType &, const char *, const char *, utils::cascade_type) {}
+  void on_has_many(const char *, ContainerType &, const char *, const char *, const utils::foreign_attributes &/*attr*/) {}
   template<class ContainerType>
-  void on_has_many(const char *, ContainerType &, utils::cascade_type) {}
+  void on_has_many(const char *, ContainerType &, const utils::foreign_attributes &/*attr*/) {}
 
   template<class Type>
   void bind(const Type &) {}
@@ -109,11 +122,11 @@ public:
     return true;
   }
 
-  [[nodiscard]] const record& prototype() const;
+  [[nodiscard]] const std::vector<column_definition>& prototype() const;
 
 protected:
   size_t column_index_ = 0;
-  record prototype_;
+  std::vector<column_definition> prototype_;
   std::unique_ptr<query_result_reader> reader_;
   detail::pk_reader pk_reader_;
 };

include/matador/sql/query_result_reader.hpp

@@ -2,10 +2,12 @@
 #define QUERY_QUERY_RESULT_READER_HPP
 
 #include "matador/sql/any_type.hpp"
-#include "matador/sql/types.hpp"
+#include "matador/sql/data_type_traits.hpp"
 
 namespace matador::sql {
 
+class value;
+
 class query_result_reader
 {
 public:
@@ -33,7 +35,8 @@ public:
   virtual void read_value(const char *id, size_t index, char *value, size_t s);
   virtual void read_value(const char *id, size_t index, std::string &value);
   virtual void read_value(const char *id, size_t index, std::string &value, size_t s);
-  virtual void read_value(const char *id, size_t index, any_type &value, data_type_t type, size_t size);
+  virtual void read_value(const char *id, size_t index, utils::blob &value);
+  virtual void read_value(const char *id, size_t index, value &val, size_t size);
 };
 
 }

include/matador/sql/record.hpp

@@ -3,29 +3,32 @@
 
 #include "matador/utils/access.hpp"
 
-#include "matador/sql/column.hpp"
+#include "matador/sql/field.hpp"
 
 #include <vector>
 #include <unordered_map>
 
 namespace matador::sql {
 
+struct column;
+
 class record
 {
 private:
-  using column_by_index = std::vector<column>;
+  using field_ref = std::reference_wrapper<field>;
-  using column_index_pair = std::pair<std::reference_wrapper<column>, size_t>;
+  using field_by_index = std::vector<field_ref>;
-  using column_by_name_map = std::unordered_map<std::string, column_index_pair>;
+  using field_index_pair = std::pair<field, field_by_index::difference_type>;
+  using field_by_name_map = std::unordered_map<std::string, field_index_pair>;
 
 public:
-  using iterator = column_by_index::iterator;
+  using iterator = field_by_index::iterator;
-  using const_iterator = column_by_index::const_iterator;
+  using const_iterator = field_by_index::const_iterator;
 
   record() = default;
-  record(std::initializer_list<column> columns);
+  record(std::initializer_list<field> columns);
-  explicit record(const std::vector<column> &columns);
+  explicit record(const std::vector<field> &columns);
-  record(const record&) = default;
+  record(const record &x);
-  record& operator=(const record&) = default;
+  record& operator=(const record &x);
   record(record&&) noexcept = default;
   record& operator=(record&&) noexcept = default;
   ~record() = default;
@@ -33,25 +36,17 @@ public:
   template<class Operator>
   void process(Operator &op)
   {
-    for(auto &col : columns_) {
+    for(auto &f : fields_) {
-      col.process(op);
+      f.get().process(op);
     }
   }
-  template < typename Type >
-  void append(const std::string &name, long size = -1)
-  {
-    append(make_column<Type>(name, size));
-  }
 
-  void append(column col);
+  void append(const field &col);
 
-  bool has_primary_key() const;
+  [[nodiscard]] const std::vector<field_ref>& columns() const;
-  const column& primary_key() const;
 
-  [[nodiscard]] const std::vector<column>& columns() const;
+  [[nodiscard]] const field& at(const column &col) const;
-
+  [[nodiscard]] const field& at(size_t index) const;
-  [[nodiscard]] const column& at(const std::string &name) const;
-  [[nodiscard]] const column& at(size_t index) const;
 
   iterator find(const std::string &column_name);
   [[nodiscard]] const_iterator find(const std::string &column_name) const;
@@ -68,15 +63,17 @@ public:
   [[nodiscard]] bool empty() const;
   void clear();
 
+//  [[nodiscard]] bool unknown() const;
+
 private:
   void init();
-  void add_to_map(column &col, size_t index);
+  void add_to_map(field &col, size_t index);
 
 private:
-  column_by_index columns_;
+  field_by_index fields_;
-  column_by_name_map columns_by_name_;
+  field_by_name_map fields_by_name_;
 
-  int pk_index_{-1};
+//  int pk_index_{-1};
 };
 
 }

include/matador/sql/result_parameter_binder.hpp

@@ -6,7 +6,7 @@
 #include "matador/utils/field_attributes.hpp"
 
 #include "matador/sql/any_type.hpp"
-#include "matador/sql/types.hpp"
+#include "matador/sql/data_type_traits.hpp"
 
 #include <string>
 

include/matador/sql/schema.hpp

@@ -0,0 +1,89 @@
+#ifndef QUERY_SCHEMA_HPP
+#define QUERY_SCHEMA_HPP
+
+#include "matador/sql/column_definition_generator.hpp"
+#include "matador/sql/table_definition.hpp"
+
+#include <optional>
+#include <string>
+#include <typeindex>
+#include <unordered_map>
+
+namespace matador::sql {
+
+class connection;
+
+struct table_info
+{
+  std::string name;
+  table_definition prototype;
+};
+
+class schema
+{
+public:
+  using repository = std::unordered_map<std::type_index, table_info>;
+  using repository_by_name = std::unordered_map<std::string, std::reference_wrapper<table_info>>;
+  using iterator = repository::iterator;
+  using const_iterator = repository::const_iterator;
+
+  schema() = delete;
+  explicit schema(std::string name);
+  schema(const schema&) = delete;
+  schema& operator=(const schema&) = delete;
+  schema(schema&&) noexcept = default;
+  schema& operator=(schema&&) noexcept = default;
+
+  [[nodiscard]] std::string name() const;
+
+  void create(connection &c);
+
+  template<typename Type>
+  const table_info& attach(const std::string &table_name)
+  {
+    return attach(std::type_index(typeid(Type)), table_info{table_name, table_definition{column_definition_generator::generate<Type>(*this)}});
+  }
+
+  const table_info& attach(std::type_index ti, const table_info& table);
+
+  template<typename Type>
+  [[nodiscard]] std::optional<table_info> info() const
+  {
+    return info(std::type_index(typeid(Type)));
+  }
+
+  [[nodiscard]] std::optional<table_info> info(std::type_index ti) const;
+  [[nodiscard]] std::optional<table_info> info(const std::string &name) const;
+
+  template<typename Type>
+  [[nodiscard]] std::pair<std::string, std::string> reference() const
+  {
+    return reference(std::type_index(typeid(Type)));
+  }
+
+  [[nodiscard]] std::pair<std::string, std::string> reference(const std::type_index &ti) const;
+
+  template<typename Type>
+  [[nodiscard]] bool exists() const
+  {
+    return exists(std::type_index(typeid(Type)));
+  }
+
+  [[nodiscard]] bool exists(const std::type_index &ti) const;
+
+  iterator begin();
+  [[nodiscard]] const_iterator begin() const;
+  iterator end();
+  [[nodiscard]] const_iterator end() const;
+
+  [[nodiscard]] bool empty() const;
+
+private:
+  std::string name_;
+  repository repository_;
+  repository_by_name repository_by_name_;
+};
+
+}
+
+#endif //QUERY_SCHEMA_HPP

include/matador/sql/session.hpp

@@ -1,13 +1,12 @@
 #ifndef QUERY_SESSION_HPP
 #define QUERY_SESSION_HPP
 
-#include "matador/sql/column_generator.hpp"
 #include "matador/sql/connection.hpp"
 #include "matador/sql/connection_pool.hpp"
-#include "matador/sql/query_builder.hpp"
+#include "matador/sql/entity.hpp"
-#include "matador/sql/query_intermediates.hpp"
+#include "matador/sql/entity_query_builder.hpp"
 #include "matador/sql/statement.hpp"
-#include "matador/sql/table_repository.hpp"
+#include "matador/sql/schema.hpp"
 
 #include <unordered_map>
 
@@ -15,56 +14,157 @@ namespace matador::sql {
 
 class dialect;
 
+enum class session_error {
+  Ok = 0,
+  NoConnectionAvailable,
+  UnknownType,
+  FailedToBuildQuery,
+  FailedToFindObject
+};
+
 class session
 {
 public:
   explicit session(connection_pool<connection> &pool);
 
-  query_create_intermediate create();
+  template<typename Type>
-  query_drop_intermediate drop();
+  void attach(const std::string &table_name);
-  template < class Type >
+
-  query_select_intermediate select();
+  void create_schema();
-  query_select_intermediate select(std::initializer_list<column> columns);
+
-  query_insert_intermediate insert();
+  template<typename Type>
-  query_update_intermediate update(const std::string &table);
+  entity<Type> insert(Type *obj);
-  query_delete_intermediate remove();
+
+  template< class Type, typename... Args >
+  entity<Type> insert(Args&&... args) {
+    return insert(new Type(std::forward<Args>(args)...));
+  }
+
+  template<typename Type, typename PrimaryKeyType>
+  utils::result<entity<Type>, session_error> find(const PrimaryKeyType &pk) {
+    auto c = pool_.acquire();
+    if (!c.valid()) {
+      return utils::error(session_error::NoConnectionAvailable);
+    }
+    auto info = schema_->info<Type>();
+    if (!info) {
+      return utils::error(session_error::UnknownType);
+    }
+
+    entity_query_builder eqb(*schema_);
+    auto data = eqb.build<Type>(pk);
+    if (!data.is_ok()) {
+      return utils::error(session_error::FailedToBuildQuery);
+    }
+
+    auto obj = build_select_query(c, data.release()).template fetch_one<Type>();
+
+    if (!obj) {
+      return utils::error(session_error::FailedToFindObject);
+    }
+    return utils::ok(entity<Type>{ obj.release() });
+  }
+
+  template<typename Type>
+  utils::result<query_result<Type>, session_error> find() {
+    auto c = pool_.acquire();
+    if (!c.valid()) {
+      return utils::error(session_error::NoConnectionAvailable);
+    }
+    auto info = schema_->info<Type>();
+    if (!info) {
+      return utils::error(session_error::UnknownType);
+    }
+
+    entity_query_builder eqb(*schema_);
+    auto data = eqb.build<Type>();
+    if (!data.is_ok()) {
+      return utils::error(session_error::FailedToBuildQuery);
+    }
+
+    return utils::ok(build_select_query(c, data.release()).template fetch_all<Type>());
+  }
+
+  template<typename Type>
+  utils::result<query_from_intermediate, session_error> select() {
+    auto c = pool_.acquire();
+    if (!c.valid()) {
+      return utils::error(session_error::NoConnectionAvailable);
+    }
+    auto info = schema_->info<Type>();
+    if (!info) {
+      return utils::error(session_error::UnknownType);
+    }
+
+    entity_query_builder eqb(*schema_);
+    auto data = eqb.build<Type>();
+    if (!data.is_ok()) {
+      return utils::error(session_error::FailedToBuildQuery);
+    }
+
+    return utils::ok(build_select_query(c, data.release()).template fetch_all<Type>());
+  }
+
+  template<typename Type>
+  void drop_table();
+  void drop_table(const std::string &table_name);
 
   [[nodiscard]] query_result<record> fetch(const query_context &q) const;
 //  [[nodiscard]] query_result<record> fetch(const std::string &sql) const;
   [[nodiscard]] size_t execute(const std::string &sql) const;
   statement prepare(query_context q) const;
 
-  record describe_table(const std::string &table_name) const;
+  std::vector<sql::column_definition> describe_table(const std::string &table_name) const;
   bool table_exists(const std::string &table_name) const;
 
-  template<typename Type>
-  void attach(const std::string &table_name)
-  {
-    table_repository_.attach<Type>(table_name);
-  }
-
-  [[nodiscard]] const table_repository& tables() const;
-
   const class dialect& dialect() const;
 
 private:
-  friend class query_select_finish;
+  friend class query_select;
 
   [[nodiscard]] std::unique_ptr<query_result_impl> fetch(const std::string &sql) const;
 
+  query_select build_select_query(connection_ptr<connection> &conn, entity_query_data &&data) const;
+
 private:
   connection_pool<connection> &pool_;
   const class dialect &dialect_;
 
-  table_repository table_repository_;
+  std::unique_ptr<schema> schema_;
-  mutable std::unordered_map<std::string, record> prototypes_;
+  mutable std::unordered_map<std::string, table_definition> prototypes_;
 };
 
-template<class Type>
+template<typename Type>
-query_select_intermediate session::select()
+void session::attach(const std::string &table_name)
 {
-  return query_select_intermediate{*this, column_generator::generate<Type>(table_repository_)};
+  schema_->attach<Type>(table_name);
+}
+
+template<typename Type>
+entity<Type> session::insert(Type *obj)
+{
+  auto c = pool_.acquire();
+  auto info = schema_->info<Type>();
+  if (!info) {
+    return {};
+  }
+  c->query(*schema_)
+    .insert()
+    .into(info->name, column_generator::generate<Type>(*schema_, true))
+    .values(*obj)
+    .execute();
+
+  return entity{obj};
+}
+
+template<typename Type>
+void session::drop_table()
+{
+  auto info = schema_->info<Type>();
+  if (info) {
+    return drop_table(info.name);
   }
 
+}
 }
 #endif //QUERY_SESSION_HPP

include/matador/sql/statement_impl.hpp

@@ -4,7 +4,7 @@
 #include "matador/sql/query_context.hpp"
 #include "matador/sql/query_result_impl.hpp"
 #include "matador/sql/parameter_binder.hpp"
-#include "matador/sql/types.hpp"
+#include "matador/sql/data_type_traits.hpp"
 
 #include <memory>
 

include/matador/sql/table.hpp

@@ -0,0 +1,41 @@
+#ifndef QUERY_TABLE_HPP
+#define QUERY_TABLE_HPP
+
+#include "matador/sql/column.hpp"
+
+#include <typeindex>
+#include <string>
+#include <vector>
+
+namespace matador::sql {
+
+struct table
+{
+  table(const char *name, std::string as = "") // NOLINT(*-explicit-constructor)
+  : name(name), alias(std::move(as)) {}
+  table(std::string name, std::string as = "") // NOLINT(*-explicit-constructor)
+  : name(std::move(name))
+  , alias(std::move(as)) {}
+  table(std::string name, std::string as, const std::vector<column> &columns)
+  : name(std::move(name))
+  , alias(std::move(as))
+  , columns(columns) {}
+
+  table& as(const std::string &a) {
+    alias = a;
+    return *this;
+  }
+
+  [[nodiscard]] table as(const std::string &a) const {
+    return { name, a, columns };
+  }
+
+  std::string name;
+  std::string alias;
+
+  std::vector<column> columns;
+};
+
+}
+
+#endif //QUERY_TABLE_HPP

include/matador/sql/table_definition.hpp

@@ -0,0 +1,73 @@
+#ifndef QUERY_TABLE_DEFINITION_HPP
+#define QUERY_TABLE_DEFINITION_HPP
+
+#include "matador/sql/column.hpp"
+#include "matador/sql/column_definition.hpp"
+
+#include <unordered_map>
+
+namespace matador::sql {
+
+class table_definition final
+{
+private:
+  using column_by_index = std::vector<column_definition>;
+  using column_index_pair = std::pair<std::reference_wrapper<column_definition>, column_by_index::difference_type>;
+  using column_by_name_map = std::unordered_map<std::string, column_index_pair>;
+
+public:
+  using iterator = column_by_index::iterator;
+  using const_iterator = column_by_index::const_iterator;
+
+  table_definition() = default;
+  table_definition(std::initializer_list<column_definition> columns);
+  explicit table_definition(const std::vector<column_definition> &columns);
+  table_definition(const table_definition &x);
+  table_definition& operator=(const table_definition &x);
+  table_definition(table_definition&&) noexcept = default;
+  table_definition& operator=(table_definition&&) noexcept = default;
+  ~table_definition() = default;
+
+  [[nodiscard]] bool has_primary_key() const;
+  [[nodiscard]] std::optional<column_definition> primary_key() const;
+
+  template < typename Type >
+  void append(const std::string &name, long size = -1)
+  {
+    append(make_column<Type>(name, size));
+  }
+  void append(column_definition col);
+
+  [[nodiscard]] const std::vector<column_definition>& columns() const;
+
+  [[nodiscard]] const column_definition& at(const column &col) const;
+  [[nodiscard]] const column_definition& at(size_t index) const;
+
+  iterator find(const std::string &column_name);
+  [[nodiscard]] const_iterator find(const std::string &column_name) const;
+
+  iterator begin();
+  [[nodiscard]] const_iterator begin() const;
+  [[nodiscard]] const_iterator cbegin() const;
+
+  iterator end();
+  [[nodiscard]] const_iterator end() const;
+  [[nodiscard]] const_iterator cend() const;
+
+  [[nodiscard]] size_t size() const;
+  [[nodiscard]] bool empty() const;
+  void clear();
+
+private:
+  void init();
+  void add_to_map(column_definition &col, size_t index);
+
+private:
+  column_by_index columns_;
+  column_by_name_map columns_by_name_;
+
+  int pk_index_{-1};
+};
+
+}
+#endif //QUERY_TABLE_DEFINITION_HPP

include/matador/sql/table_repository.hpp

@@ -1,55 +0,0 @@
-#ifndef QUERY_TABLE_REPOSITORY_HPP
-#define QUERY_TABLE_REPOSITORY_HPP
-
-#include "matador/sql/column_generator.hpp"
-#include "matador/sql/record.hpp"
-
-#include <optional>
-#include <string>
-#include <typeindex>
-#include <unordered_map>
-
-namespace matador::sql {
-
-struct table_info
-{
-  std::string name;
-  record prototype;
-};
-
-class table_repository
-{
-public:
-  template<typename Type>
-  const table_info& attach(const std::string &table_name)
-  {
-    return attach(std::type_index(typeid(Type)), table_info{table_name, record{column_generator::generate<Type>(*this)}});
-  }
-
-  const table_info& attach(std::type_index ti, const table_info& table);
-
-  template<typename Type>
-  std::optional<table_info> info()
-  {
-    return info(std::type_index(typeid(Type)));
-  }
-
-  std::optional<table_info> info(std::type_index ti);
-
-  template<typename Type>
-  [[nodiscard]] std::pair<std::string, std::string> reference() const
-  {
-    return reference(std::type_index(typeid(Type)));
-  }
-
-  [[nodiscard]] std::pair<std::string, std::string> reference(const std::type_index &ti) const;
-
-private:
-  using repository = std::unordered_map<std::type_index, table_info>;
-  repository repository_;
-};
-;
-
-}
-
-#endif //QUERY_TABLE_REPOSITORY_HPP

include/matador/sql/value.hpp

@@ -0,0 +1,81 @@
+#ifndef QUERY_VALUE_HPP
+#define QUERY_VALUE_HPP
+
+#include "matador/sql/any_type.hpp"
+#include "matador/sql/any_type_to_visitor.hpp"
+#include "matador/sql/data_type_traits.hpp"
+
+#include "matador/utils/types.hpp"
+
+#include <optional>
+
+namespace matador::sql {
+
+namespace detail {
+template<typename Type>
+size_t determine_size(const Type &/*val*/)
+{
+  return 0;
+}
+size_t determine_size(const std::string &val);
+size_t determine_size(const char *val);
+size_t determine_size(const utils::blob &val);
+
+}
+class value
+{
+public:
+  value() = default;
+  template<typename Type>
+  explicit value(Type value, size_t size = 0)
+  : size_(size)
+  , value_(value)
+  , type_(data_type_traits<Type>::builtin_type(size)) {}
+  explicit value(data_type_t data_type, size_t size = 0);
+  value(const value &x) = default;
+  value& operator=(const value &x) = default;
+  template<typename Type>
+  value& operator=(Type val)
+  {
+    value_ = val;
+    size_ = detail::determine_size(val);
+    type_ = data_type_traits<Type>::builtin_type(size_);
+    return *this;
+  }
+  value(value &&x) noexcept;
+  value& operator=(value &&x) noexcept;
+
+  template<class Type>
+  std::optional<Type> as() const
+  {
+    if (std::holds_alternative<Type>(value_)) {
+      return std::get<Type>(value_);
+    } else {
+      any_type_to_visitor<Type> visitor;
+      std::visit(visitor, const_cast<any_type &>(value_));
+      return visitor.result;
+    }
+  }
+  [[nodiscard]] std::string str() const;
+
+  [[nodiscard]] size_t size() const;
+  [[nodiscard]] data_type_t type() const;
+
+  [[nodiscard]] bool is_integer() const;
+  [[nodiscard]] bool is_floating_point() const;
+  [[nodiscard]] bool is_bool() const;
+  [[nodiscard]] bool is_string() const;
+  [[nodiscard]] bool is_varchar() const;
+  [[nodiscard]] bool is_blob() const;
+  [[nodiscard]] bool is_null() const;
+  [[nodiscard]] bool is_unknown() const;
+
+private:
+  any_type value_;
+  size_t size_{};
+  data_type_t type_{data_type_t::type_unknown};
+
+};
+
+}
+#endif //QUERY_VALUE_HPP

include/matador/sql/value_extractor.hpp

@@ -2,7 +2,9 @@
 #define QUERY_VALUE_EXTRACTOR_HPP
 
 #include "matador/sql/fk_value_extractor.hpp"
-#include "matador/sql/types.hpp"
+#include "matador/sql/data_type_traits.hpp"
+
+#include "matador/utils/foreign_attributes.hpp"
 
 #include <vector>
 
@@ -41,19 +43,21 @@ public:
   void on_attribute(const char *id, std::string &x, const utils::field_attributes &/*attr*/ = utils::null_attributes);
 
   template<class Type, template < class ... > class Pointer>
-  void on_belongs_to(const char * /*id*/, Pointer<Type> &x, utils::cascade_type)
+  void on_belongs_to(const char * /*id*/, Pointer<Type> &x, const utils::foreign_attributes &/*attr*/)
   {
     values_.emplace_back(fk_value_extractor_.extract(*x));
   }
   template<class Type, template < class ... > class Pointer>
-  void on_has_one(const char * /*id*/, Pointer<Type> &x, utils::cascade_type)
+  void on_has_one(const char * /*id*/, Pointer<Type> &x, const utils::foreign_attributes &/*attr*/)
   {
     values_.emplace_back(fk_value_extractor_.extract(*x));
   }
   template<class ContainerType>
-  void on_has_many(const char *, ContainerType &, const char *, const char *, utils::cascade_type) {}
+  void on_has_many(ContainerType &, const char *, const utils::foreign_attributes &/*attr*/) {}
   template<class ContainerType>
-  void on_has_many(const char *, ContainerType &, utils::cascade_type) {}
+  void on_has_many_to_many(const char *id, ContainerType &c, const char *join_column, const char *inverse_join_column, const utils::foreign_attributes &/*attr*/) {}
+  template<class ContainerType>
+  void on_has_many_to_many(const char *id, ContainerType &c, const utils::foreign_attributes &/*attr*/) {}
 
 private:
   template<typename Type>

include/matador/utils/access.hpp

@@ -1,9 +1,8 @@
 #ifndef QUERY_ACCESS_HPP
 #define QUERY_ACCESS_HPP
 
-#include "matador/utils/cascade_type.hpp"
-
 #include <string>
+#include <optional>
 
 namespace matador::utils {
 
@@ -11,6 +10,7 @@ template < class Type, template < class ... > class ContainerType >
 class container;
 
 class field_attributes;
+class foreign_attributes;
 
 namespace access {
 
@@ -44,29 +44,39 @@ void attribute(Operator &op, const char *id, Type &value, const field_attributes
   op.on_attribute(id, value, attr);
 }
 
+template<class Operator, class Type>
+void attribute(Operator &op, const char *id, std::optional<Type> &value, const field_attributes &attr) {
+  op.on_attribute(id, value, attr);
+}
+
 template<class Operator, class Type>
 void attribute(Operator &op, const char *id, Type &value) {
   op.on_attribute(id, value);
 }
 
 template<class Operator, class Type>
-void has_one(Operator &op, const char *id, Type &value, cascade_type cascade) {
+void has_one(Operator &op, const char *id, Type &value, const foreign_attributes &attr) {
-  op.on_has_one(id, value, cascade);
+  op.on_has_one(id, value, attr);
 }
 
 template<class Operator, class Type>
-void belongs_to(Operator &op, const char *id, Type &value, cascade_type cascade) {
+void belongs_to(Operator &op, const char *id, Type &value, const foreign_attributes &attr) {
-  op.on_belongs_to(id, value, cascade);
+  op.on_belongs_to(id, value, attr);
 }
 
 template<class Operator, class Type, template<class ...> class ContainerType>
-void has_many(Operator &op, const char *id, container<Type, ContainerType> &container, cascade_type cascade) {
+void has_many(Operator &op, ContainerType<Type> &container, const char *join_column, const foreign_attributes &attr) {
-  op.on_has_many(id, container, cascade);
+  op.on_has_many(container, join_column, attr);
 }
 
 template<class Operator, class Type, template<class ...> class ContainerType>
-void has_many(Operator &op, const char *id, container<Type, ContainerType> &container, const char *left_column, const char *right_column, cascade_type cascade) {
+void has_many_to_many(Operator &op, const char *id, ContainerType<Type> &container, const char *join_column, const char *inverse_join_column, const foreign_attributes &attr) {
-  op.on_has_many(id, container, left_column, right_column, cascade);
+  op.on_has_many_to_many(id, container, join_column, inverse_join_column, attr);
+}
+
+template<class Operator, class Type, template<class ...> class ContainerType>
+void has_many_to_many(Operator &op, const char *id, ContainerType<Type> &container, const foreign_attributes &attr) {
+  op.on_has_many_to_many(id, container, attr);
 }
 
 }

include/matador/utils/constraints.hpp

@@ -5,14 +5,12 @@ namespace matador::utils {
 
 enum class constraints : unsigned char {
   NONE =           0,
-  NOT_NULL =       1 << 0,
   INDEX =          1 << 1,
   UNIQUE =         1 << 2,
   PRIMARY_KEY =    1 << 3,
   FOREIGN_KEY =    1 << 4,
   DEFAULT =        1 << 5,
-  AUTO_INCREMENT = 1 << 6,
+  AUTO_INCREMENT = 1 << 6
-  UNIQUE_NOT_NULL = UNIQUE | NOT_NULL
 };
 
 //static std::unordered_map<constraints, std::string> constraints_to_name_map();

include/matador/utils/fetch_type.hpp

@@ -0,0 +1,21 @@
+#ifndef QUERY_FETCH_TYPE_HPP
+#define QUERY_FETCH_TYPE_HPP
+
+#include <cstdint>
+
+namespace matador::utils {
+
+/**
+ * @brief Defines fetch types
+ *
+ * Defines fetch types for foreign relations
+ */
+enum class fetch_type : uint8_t
+{
+  LAZY,   /**< Indicates lazy fetch */
+  EAGER   /**< Indicates eager fetch */
+};
+
+}
+
+#endif //QUERY_FETCH_TYPE_HPP

include/matador/utils/foreign_attributes.hpp

@@ -0,0 +1,34 @@
+#ifndef QUERY_FOREIGN_ATTRIBUTES_HPP
+#define QUERY_FOREIGN_ATTRIBUTES_HPP
+
+#include "matador/utils/fetch_type.hpp"
+#include "matador/utils/cascade_type.hpp"
+
+namespace matador::utils {
+
+class foreign_attributes
+{
+public:
+  foreign_attributes() = default;
+  foreign_attributes(cascade_type cascade); // NOLINT(*-explicit-constructor)
+  foreign_attributes(fetch_type fetch); // NOLINT(*-explicit-constructor)
+  foreign_attributes(cascade_type cascade, fetch_type fetch);
+  foreign_attributes(const foreign_attributes &x) = default;
+  foreign_attributes& operator=(const foreign_attributes &x) = default;
+  foreign_attributes(foreign_attributes &&x) = default;
+  foreign_attributes& operator=(foreign_attributes &&x) = default;
+  ~foreign_attributes() = default;
+
+  [[nodiscard]] cascade_type cascade() const;
+  [[nodiscard]] fetch_type fetch() const;
+
+private:
+  cascade_type cascade_{cascade_type::NONE};
+  fetch_type fetch_{fetch_type::LAZY};
+};
+
+const foreign_attributes default_foreign_attributes {};
+
+}
+
+#endif //QUERY_FOREIGN_ATTRIBUTES_HPP

include/matador/utils/macro_map.hpp

@@ -0,0 +1,42 @@
+#ifndef QUERY_MACRO_MAP_HPP
+#define QUERY_MACRO_MAP_HPP
+
+#define EVAL0(...) __VA_ARGS__
+#define EVAL1(...) EVAL0(EVAL0(EVAL0(__VA_ARGS__)))
+#define EVAL2(...) EVAL1(EVAL1(EVAL1(__VA_ARGS__)))
+#define EVAL3(...) EVAL2(EVAL2(EVAL2(__VA_ARGS__)))
+#define EVAL4(...) EVAL3(EVAL3(EVAL3(__VA_ARGS__)))
+#define EVAL(...)  EVAL4(EVAL4(EVAL4(__VA_ARGS__)))
+
+#define MAP_END(...)
+#define MAP_OUT
+#define MAP_COMMA ,
+
+#define MAP_GET_END2() 0, MAP_END
+#define MAP_GET_END1(...) MAP_GET_END2
+#define MAP_GET_END(...) MAP_GET_END1
+#define MAP_NEXT0(test, next, ...) next MAP_OUT
+#define MAP_NEXT1(test, next) MAP_NEXT0(test, next, 0)
+#define MAP_NEXT(test, next)  MAP_NEXT1(MAP_GET_END test, next)
+
+#define MAP0(f, x, peek, ...) f(x) MAP_NEXT(peek, MAP1)(f, peek, __VA_ARGS__)
+#define MAP1(f, x, peek, ...) f(x) MAP_NEXT(peek, MAP0)(f, peek, __VA_ARGS__)
+
+#define MAP_LIST_NEXT1(test, next) MAP_NEXT0(test, MAP_COMMA next, 0)
+#define MAP_LIST_NEXT(test, next)  MAP_LIST_NEXT1(MAP_GET_END test, next)
+
+#define MAP_LIST0(f, x, peek, ...) f(x) MAP_LIST_NEXT(peek, MAP_LIST1)(f, peek, __VA_ARGS__)
+#define MAP_LIST1(f, x, peek, ...) f(x) MAP_LIST_NEXT(peek, MAP_LIST0)(f, peek, __VA_ARGS__)
+
+/**
+ * Applies the function macro `f` to each of the remaining parameters.
+ */
+#define MAP(f, ...) EVAL(MAP1(f, __VA_ARGS__, ()()(), ()()(), ()()(), 0))
+
+/**
+ * Applies the function macro `f` to each of the remaining parameters and
+ * inserts commas between the results.
+ */
+#define MAP_LIST(f, ...) EVAL(MAP_LIST1(f, __VA_ARGS__, ()()(), ()()(), ()()(), 0))
+
+#endif //QUERY_MACRO_MAP_HPP

include/matador/utils/result.hpp

@@ -0,0 +1,113 @@
+#ifndef QUERY_RESULT_HPP
+#define QUERY_RESULT_HPP
+
+#include <variant>
+
+namespace matador::utils {
+
+template < typename ValueType, typename ErrorType >
+class [[nodiscard]] result;
+
+template <typename ValueType>
+struct is_result : std::false_type {};
+
+template < typename ValueType, typename ErrorType >
+struct is_result<result<ValueType, ErrorType>> : std::true_type {};
+
+template < typename ValueType >
+class ok
+{
+public:
+  using value_type = ValueType;
+  explicit constexpr ok(const ValueType &value) : value_(value) {}
+  explicit constexpr ok(ValueType &&value) : value_(std::move(value)) {}
+
+  constexpr ValueType&& release() { return std::move(value_); }
+  const ValueType& value() const { return value_; }
+  ValueType& value() { return value_; }
+
+private:
+  ValueType value_;
+};
+
+template < typename ErrorType >
+class error
+{
+public:
+  using value_type = ErrorType;
+
+  explicit constexpr error(const ErrorType &error) : error_(error) {}
+  explicit constexpr error(ErrorType &&error) : error_(std::move(error)) {}
+
+  constexpr ErrorType&& release() { return std::move(error_); }
+  const ErrorType& value() const { return error_; }
+  ErrorType value() { return error_; }
+
+private:
+  ErrorType error_;
+};
+
+template < typename ValueType, typename ErrorType >
+class result
+{
+public:
+  using value_type = ok<ValueType>;
+  using error_type = error<ErrorType>;
+
+  result() : result_(ValueType{}) {}
+  result(value_type value) : result_(std::move(value)) {} // NOLINT(*-explicit-constructor)
+  result(error_type error) : result_(std::move(error)) {} // NOLINT(*-explicit-constructor)
+  result(const result<ValueType, ErrorType> &x) = default;
+  result& operator=(const result<ValueType, ErrorType> &x) = default;
+  result(result<ValueType, ErrorType> &&x) = default;
+  result& operator=(result<ValueType, ErrorType> &&x) = default;
+
+  operator bool() const { return is_ok(); } // NOLINT(*-explicit-constructor)
+
+  [[nodiscard]] bool is_ok() const { return std::holds_alternative<value_type>(result_); }
+  [[nodiscard]] bool is_error() const { return std::holds_alternative<error_type>(result_); }
+
+  ValueType&& release() { return std::get<value_type>(result_).release(); }
+  ErrorType&& release_error() { return std::get<error_type>(result_).release(); }
+
+  const ValueType& value() const { return std::get<value_type>(result_).value(); }
+  const ErrorType& err() const { return std::get<error_type>(result_).value(); }
+  ErrorType err() { return std::get<error_type>(result_).value(); }
+
+  constexpr const ValueType* operator->() const { return &value(); }
+  constexpr ValueType* operator->() { return &std::get<value_type>(result_).value(); }
+
+  template<typename Func, typename SecondValueType = typename std::invoke_result_t<Func, ValueType >>
+  result<SecondValueType, ErrorType> transform(Func &&f) {
+    if (is_ok()) {
+      return result<SecondValueType, ErrorType>(ok(f(release())));
+    }
+
+    return result<SecondValueType, ErrorType>(error(release_error()));
+  }
+
+  template<typename Func, typename SecondValueType = typename std::invoke_result_t<Func, ValueType >::value_type::value_type>
+  result<SecondValueType, ErrorType> and_then(Func &&f) {
+    if (is_ok()) {
+      return f(release());
+    }
+
+    return result<SecondValueType, ErrorType>(error(release_error()));
+  }
+
+  template<typename Func, typename SecondErrorType = typename std::invoke_result_t<Func, ErrorType >::error_type::value_type>
+  result<ValueType, SecondErrorType> or_else(Func &&f) {
+    if (is_error()) {
+      return f(err());
+    }
+
+    return result<ValueType, SecondErrorType>(ok(release()));
+  }
+
+private:
+  std::variant<value_type, error_type> result_;
+};
+
+}
+
+#endif //QUERY_RESULT_HPP

include/matador/utils/string.hpp

@@ -1,6 +1,8 @@
 #ifndef QUERY_STRING_HPP
 #define QUERY_STRING_HPP
 
+#include "matador/utils/types.hpp"
+
 #include <string>
 #include <vector>
 
@@ -13,10 +15,9 @@ namespace matador::utils {
  *
  * @param str The string to split.
  * @param delim The delimiter character.
- * @param values The result vector.
+ * @return The the vector with split strings.
- * @return The size of the vector.
  */
-size_t split(const std::string &str, char delim, std::vector<std::string> &values);
+std::vector<std::string> split(const std::string &str, char delim);
 
 /**
  * Replaces all occurrences of string from in given string
@@ -29,6 +30,7 @@ size_t split(const std::string &str, char delim, std::vector<std::string> &value
 void replace_all(std::string &in, const std::string &from, const std::string &to);
 
 const std::string& to_string(const std::string &str);
+std::string to_string(const blob &data);
 
 /**
  * Joins a range of elements as string within a list
@@ -36,7 +38,7 @@ const std::string& to_string(const std::string &str);
  * given stream
  *
  * @tparam R Type og the range (e.g. map, list, vector, etc)
- * @param range The range with the elements to join
+ * @param range The range with the elements to join_left
  * @param delim The delimiter for the elements
  * @return The ostream reference
  */

include/matador/utils/types.hpp

@@ -0,0 +1,13 @@
+#ifndef QUERY_UTILS_TYPES_HPP
+#define QUERY_UTILS_TYPES_HPP
+
+#include <vector>
+
+namespace matador::utils {
+
+using byte = unsigned char;
+using blob = std::vector<byte>;
+
+}
+
+#endif //QUERY_UTILS_TYPES_HPP

src/CMakeLists.txt

@@ -1,7 +1,7 @@
 set(SQL_SOURCES
   sql/dialect.cpp
   sql/query_builder.cpp
-  sql/column.cpp
+  sql/column_definition.cpp
   sql/key_value_pair.cpp
   sql/basic_condition.cpp
   sql/connection.cpp
@@ -12,12 +12,11 @@ set(SQL_SOURCES
   sql/session.cpp
   sql/backend_provider.cpp
   sql/query_result_impl.cpp
+  sql/column_definition_generator.cpp
   sql/column_generator.cpp
-  sql/column_name_generator.cpp
   sql/key_value_generator.cpp
   sql/fk_value_extractor.cpp
-  sql/table_repository.cpp
+  sql/schema.cpp
-  sql/any_type_to_visitor.cpp
   sql/query_result.cpp
   sql/query_result_reader.cpp
   sql/statement_cache.cpp
@@ -25,15 +24,28 @@ set(SQL_SOURCES
   sql/dialect_builder.cpp
   sql/object_parameter_binder.cpp
   sql/placeholder_generator.cpp
-  sql/types.cpp
+  sql/data_type_traits.cpp
   sql/result_parameter_binder.cpp
+  sql/statement.cpp
+  sql/convert.cpp
+  sql/column.cpp
+  sql/query.cpp
+  sql/query_parts.cpp
+  sql/query_compiler.cpp
+  sql/noop_connection.cpp
+  sql/query_part.cpp
+  sql/any_type_to_string_visitor.cpp
+  sql/field.cpp
+  sql/table_definition.cpp
+  sql/value.cpp
+  sql/entity_query_builder.cpp
 )
 
 set(SQL_HEADER
   ../include/matador/sql/dialect.hpp
   ../include/matador/sql/query_builder.hpp
-  ../include/matador/sql/column.hpp
+  ../include/matador/sql/column_definition.hpp
-  ../include/matador/sql/types.hpp
+  ../include/matador/sql/data_type_traits.hpp
   ../include/matador/sql/key_value_pair.hpp
   ../include/matador/sql/basic_condition.hpp
   ../include/matador/sql/condition.hpp
@@ -47,14 +59,14 @@ set(SQL_HEADER
   ../include/matador/sql/session.hpp
   ../include/matador/sql/backend_provider.hpp
   ../include/matador/sql/query_result_impl.hpp
+  ../include/matador/sql/column_definition_generator.hpp
   ../include/matador/sql/column_generator.hpp
-  ../include/matador/sql/column_name_generator.hpp
   ../include/matador/sql/value_extractor.hpp
   ../include/matador/sql/any_type.hpp
   ../include/matador/sql/key_value_generator.hpp
   ../include/matador/sql/entity.hpp
   ../include/matador/sql/fk_value_extractor.hpp
-  ../include/matador/sql/table_repository.hpp
+  ../include/matador/sql/schema.hpp
   ../include/matador/sql/any_type_to_visitor.hpp
   ../include/matador/sql/query_result_reader.hpp
   ../include/matador/sql/to_value.hpp
@@ -62,12 +74,27 @@ set(SQL_HEADER
   ../include/matador/sql/statement.hpp
   ../include/matador/sql/statement_impl.hpp
   ../include/matador/sql/query_context.hpp
-  sql/statement.cpp
   ../include/matador/sql/parameter_binder.hpp
   ../include/matador/sql/dialect_builder.hpp
   ../include/matador/sql/object_parameter_binder.hpp
   ../include/matador/sql/placeholder_generator.hpp
   ../include/matador/sql/result_parameter_binder.hpp
+  ../include/matador/sql/convert.hpp
+  ../include/matador/sql/query.hpp
+  ../include/matador/sql/query_parts.hpp
+  ../include/matador/sql/query_part_visitor.hpp
+  ../include/matador/sql/query_compiler.hpp
+  ../include/matador/sql/query_data.hpp
+  ../include/matador/sql/table.hpp
+  ../include/matador/sql/noop_connection.hpp
+  ../include/matador/sql/query_part.hpp
+  ../include/matador/sql/any_type_to_string_visitor.hpp
+  ../include/matador/sql/query_helper.hpp
+  ../include/matador/sql/field.hpp
+  ../include/matador/sql/entity_query_builder.hpp
+  ../include/matador/sql/table_definition.hpp
+  ../include/matador/sql/has_many_to_many_relation.hpp
+  ../include/matador/sql/value.hpp
 )
 
 set(UTILS_HEADER
@@ -80,7 +107,12 @@ set(UTILS_HEADER
   ../include/matador/utils/identifier.hpp
   ../include/matador/utils/cascade_type.hpp
   ../include/matador/utils/logger.hpp
-  ../include/matador/utils/enum_mapper.hpp)
+  ../include/matador/utils/enum_mapper.hpp
+  ../include/matador/utils/types.hpp
+  ../include/matador/utils/foreign_attributes.hpp
+  ../include/matador/utils/fetch_type.hpp
+  ../include/matador/utils/result.hpp
+)
 
 set(UTILS_SOURCES
   utils/field_attributes.cpp
@@ -90,8 +122,13 @@ set(UTILS_SOURCES
   utils/os.cpp
   utils/identifier.cpp
   sql/value_extractor.cpp
-  utils/logger.cpp)
+  utils/logger.cpp
+  utils/foreign_attributes.cpp
+)
+
+add_library(matador STATIC
+  ${SQL_SOURCES} ${SQL_HEADER}
+  ${UTILS_SOURCES} ${UTILS_HEADER}
+)
 
-add_library(matador STATIC ${SQL_SOURCES} ${SQL_HEADER} ${UTILS_SOURCES} ${UTILS_HEADER})
 target_include_directories(matador PUBLIC ${PROJECT_SOURCE_DIR}/include)
-#set_target_properties(matador PROPERTIES LINKER_LANGUAGE CXX)

src/sql/any_type_to_string_visitor.cpp

@@ -0,0 +1,40 @@
+#include "matador/sql/any_type_to_string_visitor.hpp"
+
+#include "matador/sql/dialect.hpp"
+#include "matador/sql/query_context.hpp"
+
+#include "matador/utils/string.hpp"
+
+namespace matador::sql {
+
+any_type_to_string_visitor::any_type_to_string_visitor(const dialect &d, query_context &query)
+: d(d), query(query)
+{}
+
+void any_type_to_string_visitor::to_string(const char *val)
+{
+  result = "'" + d.prepare_literal(val) + "'";
+}
+
+void any_type_to_string_visitor::to_string(std::string &val)
+{
+  result = "'" + d.prepare_literal(val) + "'";
+}
+
+void any_type_to_string_visitor::to_string(utils::blob &val)
+{
+  // "This is a binary Data string" as binary data:
+  // MySQL:    X'5468697320697320612062616E617279204461746120737472696E67'
+  // Postgres: E'\\x5468697320697320612062616E617279204461746120737472696E67'
+  // MSSQL:    0x5468697320697320612062616E617279204461746120737472696E67
+  // Sqlite:   X'5468697320697320612062616E617279204461746120737472696E67'
+  result = d.token_at(dialect::token_t::BEGIN_BINARY_DATA) + utils::to_string(val) + d.token_at(dialect::token_t::END_BINARY_DATA);
+}
+
+void any_type_to_string_visitor::to_string(placeholder &/*val*/)
+{
+  query.bind_vars.emplace_back("unknown");
+  result = d.next_placeholder(query.bind_vars);
+}
+
+}