From b255ae22b4d36082eb188315965dc88e05b1cfa3 Mon Sep 17 00:00:00 2001
From: Sascha Kuehl <skuehl1972@gmail.com>
Date: Mon, 19 Feb 2024 22:57:43 +0100
Subject: [PATCH] added query helper macro and join query parts

---
 CMakeLists.txt                              |  4 ++
 demo/macro_map.hpp                          | 42 +++++++++++++++++
 demo/main.cpp                               | 21 +++++++--
 demo/query_helper.hpp                       | 52 +++++++++++++++++++++
 include/matador/sql/query_compiler.hpp      |  2 +
 include/matador/sql/query_intermediates.hpp | 13 ++++--
 include/matador/sql/query_part_visitor.hpp  |  4 ++
 include/matador/sql/query_parts.hpp         | 39 ++++++++++++++--
 include/matador/sql/schema.hpp              |  2 +-
 include/matador/sql/table.hpp               | 12 ++++-
 src/sql/dialect.cpp                         |  1 -
 src/sql/query_compiler.cpp                  | 29 +++++++++++-
 src/sql/query_intermediates.cpp             | 14 ++----
 src/sql/query_parts.cpp                     | 31 +++++++++---
 14 files changed, 234 insertions(+), 32 deletions(-)
 create mode 100644 demo/macro_map.hpp
 create mode 100644 demo/query_helper.hpp

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 1d7ed0d..c17fff8 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -11,6 +11,10 @@ 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)
diff --git a/demo/macro_map.hpp b/demo/macro_map.hpp
new file mode 100644
index 0000000..dee5f31
--- /dev/null
+++ b/demo/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
diff --git a/demo/main.cpp b/demo/main.cpp
index 21b5036..cb93c28 100644
--- a/demo/main.cpp
+++ b/demo/main.cpp
@@ -6,6 +6,9 @@
 
 #include "matador/utils/access.hpp"
 
+#include "query_helper.hpp"
+
+#include <iostream>
 #include <string>
 
 struct author
@@ -46,26 +49,36 @@ struct book
   }
 };
 
+QUERY_HELPER(author, id, first_name, last_name, date_of_birth, year_of_birth, distinguished)
+QUERY_HELPER(book, id, book_author, title, published_in)
+
 int main()
 {
   using namespace matador::sql;
+
   const std::string env_var{"MATADOR_BACKENDS_PATH"};
 
   std::string dns{"sqlite://demo.db"};
 //  std::string dns{"memory://test"};
   auto s = std::make_shared<schema>();
+  s->attach<author>("authors");
+  s->attach<book>("books");
+
   connection c(dns, s);
 
   auto books = c.query()
-    .select<book>({"author.name"})
-    .from("book")
-    .join_left("author")
+    .select<book>({qh::book.id.name})
+    .from({"book"})
+    .join_left({"authors"})
     .on("book.author_id"_col == "author.id"_col)
     .where("book.published_in"_col < 2008 && "author.name"_col == "Michael Crichton")
     .order_by("book.title").asc()
     .offset(2)
     .limit(5)
-    .fetch_all<book>();
+    .str();
+//    .fetch_all<book>();
+
+  std::cout << "SQL: " << books << "\n";
 
   // SELECT book.title, book.id, book.author_id, book.published_in, author.name
   // FROM book
diff --git a/demo/query_helper.hpp b/demo/query_helper.hpp
new file mode 100644
index 0000000..73eeaa7
--- /dev/null
+++ b/demo/query_helper.hpp
@@ -0,0 +1,52 @@
+#ifndef QUERY_QUERY_HELPER_HPP
+#define QUERY_QUERY_HELPER_HPP
+
+#include "macro_map.hpp"
+
+#include <string>
+#include <ostream>
+
+template<typename QueryClass>
+struct basic_query;
+
+struct table {
+  template<typename QueryClass>
+  table(const basic_query<QueryClass> &qc);
+  const std::string name;
+};
+
+struct field {
+  const std::string name;
+
+  friend std::ostream& operator<<(std::ostream &out, const field &f) {
+    out << f.name;
+    return out;
+  }
+};
+
+template<typename QueryClass>
+struct basic_query {
+  const table& operator()() const {
+    return table_;
+  }
+
+  const table table_;
+};
+
+template<typename QueryClass>
+table::table(const basic_query<QueryClass>&)
+: name(QueryClass::internal_table_name_) {
+}
+
+#define FIELD(x) const field x{#x};
+
+#define QUERY_HELPER(C, ...) \
+namespace qh {     \
+namespace internal {                      \
+struct C##_query {           \
+MAP(FIELD, __VA_ARGS__) \
+}; }                     \
+static const internal:: C##_query C;  \
+}
+
+#endif //QUERY_QUERY_HELPER_HPP
diff --git a/include/matador/sql/query_compiler.hpp b/include/matador/sql/query_compiler.hpp
index 11c9da4..3d30834 100644
--- a/include/matador/sql/query_compiler.hpp
+++ b/include/matador/sql/query_compiler.hpp
@@ -24,6 +24,8 @@ public:
 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;
diff --git a/include/matador/sql/query_intermediates.hpp b/include/matador/sql/query_intermediates.hpp
index 3d5b5fc..57d67e1 100644
--- a/include/matador/sql/query_intermediates.hpp
+++ b/include/matador/sql/query_intermediates.hpp
@@ -73,7 +73,7 @@ public:
 
   statement prepare();
 
-  std::string str() const;
+  [[nodiscard]] std::string str() const;
 
 private:
   std::unique_ptr<query_result_impl> fetch();
@@ -148,7 +148,12 @@ class query_join_intermediate : public query_intermediate
 public:
   using query_intermediate::query_intermediate;
 
-  query_on_intermediate on(const basic_condition &cond);
+  template<class Condition>
+  query_on_intermediate on(const Condition &cond)
+  {
+    data_.parts.push_back(std::make_unique<query_on_part>(cond));
+    return {connection_, data_};
+  }
 };
 
 class query_from_intermediate : public query_select_finish
@@ -156,7 +161,7 @@ class query_from_intermediate : public query_select_finish
 public:
   using query_select_finish::query_select_finish;
 
-  query_join_intermediate join_left(const std::string &join_table_name, const std::string &as = "");
+  query_join_intermediate join_left(const table &t);
   query_where_intermediate where(const basic_condition &cond);
   query_group_by_intermediate group_by(const std::string &name);
   query_order_by_intermediate order_by(const std::string &name);
@@ -176,7 +181,7 @@ class query_select_intermediate : public query_start_intermediate
 public:
   query_select_intermediate(connection &s, 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 >
diff --git a/include/matador/sql/query_part_visitor.hpp b/include/matador/sql/query_part_visitor.hpp
index 1823945..c57b39c 100644
--- a/include/matador/sql/query_part_visitor.hpp
+++ b/include/matador/sql/query_part_visitor.hpp
@@ -5,6 +5,8 @@ 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;
@@ -24,6 +26,8 @@ public:
 
   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;
diff --git a/include/matador/sql/query_parts.hpp b/include/matador/sql/query_parts.hpp
index d95caf6..3464766 100644
--- a/include/matador/sql/query_parts.hpp
+++ b/include/matador/sql/query_parts.hpp
@@ -1,10 +1,12 @@
 #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/dialect.hpp"
+#include "matador/sql/table.hpp"
 
 #include <memory>
 
@@ -46,15 +48,44 @@ private:
 class query_from_part : public query_part
 {
 public:
-  explicit query_from_part(std::string table_name);
-  query_from_part(std::string table_name, std::string as);
+  explicit query_from_part(sql::table t);
+
+  [[nodiscard]] const sql::table& table() const;
 
 private:
   void accept(query_part_visitor &visitor) override;
 
 private:
-  std::string table_;
-  std::string alias_;
+  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)) {}
+
+private:
+  void accept(query_part_visitor &visitor) override;
+
+private:
+  std::unique_ptr<basic_condition> condition_;
 };
 
 class query_where_part : public query_part
diff --git a/include/matador/sql/schema.hpp b/include/matador/sql/schema.hpp
index 952bbf1..4f39d4e 100644
--- a/include/matador/sql/schema.hpp
+++ b/include/matador/sql/schema.hpp
@@ -28,7 +28,7 @@ public:
   using iterator = repository::iterator;
   using const_iterator = repository::const_iterator;
 
-  std::string name() const;
+  [[nodiscard]] std::string name() const;
 
   template<typename Type>
   const table_info& attach(const std::string &table_name)
diff --git a/include/matador/sql/table.hpp b/include/matador/sql/table.hpp
index 2e440b2..7a57ee3 100644
--- a/include/matador/sql/table.hpp
+++ b/include/matador/sql/table.hpp
@@ -8,8 +8,18 @@ namespace matador::sql {
 
 struct table
 {
-  std::type_index index;
+//  std::type_index index;
   std::string name;
+  std::string alias;
+
+  table(std::string name, std::string as = "") // NOLINT(*-explicit-constructor)
+  : name(std::move(name)), alias(std::move(as)) {}
+
+  table& as(const std::string &a) {
+    alias = a;
+    return *this;
+  }
+
 };
 
 }
diff --git a/src/sql/dialect.cpp b/src/sql/dialect.cpp
index 6a43e57..7c24402 100644
--- a/src/sql/dialect.cpp
+++ b/src/sql/dialect.cpp
@@ -1,5 +1,4 @@
 #include "matador/sql/dialect.hpp"
-#include "matador/sql/column_definition.hpp"
 
 #include "matador/utils/string.hpp"
 
diff --git a/src/sql/query_compiler.cpp b/src/sql/query_compiler.cpp
index eb94628..3c32ad1 100644
--- a/src/sql/query_compiler.cpp
+++ b/src/sql/query_compiler.cpp
@@ -6,12 +6,12 @@
 namespace matador::sql {
 
 query_compiler::query_compiler(const sql::dialect &d)
-  : dialect_(d)
+: dialect_(d)
 {}
 
 query_context query_compiler::compile(const query_data *data)
 {
-  for (const auto &part : data->parts) {
+  for (const auto &part: data->parts) {
     part->accept(*this);
   }
 
@@ -20,6 +20,10 @@ query_context query_compiler::compile(const query_data *data)
 
 void query_compiler::visit(query_select_part &select_part)
 {
+  query_.sql = dialect_.token_at(dialect::token_t::SELECT) + " ";
+
+  query_.prototype.clear();
+
   std::string result;
   const auto &columns = select_part.columns();
   if (columns.size() < 2) {
@@ -40,9 +44,30 @@ void query_compiler::visit(query_select_part &select_part)
       query_.prototype.append(column_definition{(*it).name});
     }
   }
+
+  query_.sql += result;
 }
 
 void query_compiler::visit(query_from_part &from_part)
+{
+  if (dialect_.default_schema_name().empty()) {
+    query_.sql += " " + dialect_.token_at(dialect::token_t::FROM) +
+                  " " + dialect_.prepare_identifier(from_part.table().name) +
+                  (from_part.table().alias.empty() ? "" : " AS " + dialect_.prepare_identifier(from_part.table().alias));
+  } else {
+    query_.sql += " " + dialect_.token_at(dialect::token_t::FROM) +
+                  " " + dialect_.prepare_identifier(dialect_.default_schema_name()) +
+                  "." + dialect_.prepare_identifier(from_part.table().name) +
+                  (from_part.table().alias.empty() ? "" : " AS " + dialect_.prepare_identifier(from_part.table().alias));
+  }
+}
+
+void query_compiler::visit(query_join_part &join_part)
+{
+
+}
+
+void query_compiler::visit(query_on_part &on_part)
 {
 
 }
diff --git a/src/sql/query_intermediates.cpp b/src/sql/query_intermediates.cpp
index 92a58c3..68f4108 100644
--- a/src/sql/query_intermediates.cpp
+++ b/src/sql/query_intermediates.cpp
@@ -1,6 +1,7 @@
 #include "matador/sql/query_intermediates.hpp"
 #include "matador/sql/session.hpp"
 #include "matador/sql/query_compiler.hpp"
+#include "matador/sql/condition.hpp"
 
 namespace matador::sql {
 basic_query_intermediate::basic_query_intermediate(connection &db)
@@ -125,16 +126,10 @@ query_order_by_intermediate query_on_intermediate::order_by(const std::string &n
 //  return {connection_, builder_.order_by(name)};
 }
 
-query_on_intermediate query_join_intermediate::on(const basic_condition &cond)
+query_join_intermediate query_from_intermediate::join_left(const table &t)
 {
+  data_.parts.push_back(std::make_unique<query_join_part>(t));
   return {connection_, data_};
-//  return {connection_, builder_.on(column, join_column)};
-}
-
-query_join_intermediate query_from_intermediate::join_left(const std::string &join_table_name, const std::string &as)
-{
-  return {connection_, data_};
-//  return {connection_, builder_.join(join_table_name, join_type_t::INNER, as)};
 }
 
 query_where_intermediate query_from_intermediate::where(const basic_condition &cond)
@@ -149,8 +144,9 @@ query_select_intermediate::query_select_intermediate(connection &db, const std::
   data_.parts.push_back(std::make_unique<query_select_part>(columns));
 }
 
-query_from_intermediate query_select_intermediate::from(const std::string &table, const std::string &as)
+query_from_intermediate query_select_intermediate::from(const table& t)
 {
+  data_.parts.push_back(std::make_unique<query_from_part>(t));
   return {connection_, data_};
 //  return {connection_, builder_.from(table, as)};
 }
diff --git a/src/sql/query_parts.cpp b/src/sql/query_parts.cpp
index a40c706..8ba7fc6 100644
--- a/src/sql/query_parts.cpp
+++ b/src/sql/query_parts.cpp
@@ -20,20 +20,39 @@ const std::vector<column>& query_select_part::columns() const
   return columns_;
 }
 
-query_from_part::query_from_part(std::string table_name)
+query_from_part::query_from_part(sql::table t)
   : query_part(sql::dialect::token_t::FROM)
-  , table_(std::move(table_name)) {}
+  , table_(std::move(t)) {}
 
-query_from_part::query_from_part(std::string table_name, std::string as)
-  : query_part(sql::dialect::token_t::FROM)
-  , table_(std::move(table_name))
-  , alias_(std::move(as)) {}
+const sql::table &query_from_part::table() const
+{
+  return table_;
+}
 
 void query_from_part::accept(query_part_visitor &visitor)
 {
   visitor.visit(*this);
 }
 
+query_join_part::query_join_part(sql::table t)
+  : query_part(sql::dialect::token_t::JOIN)
+  , table_(std::move(t)) {}
+
+const sql::table &query_join_part::table() const
+{
+  return table_;
+}
+
+void query_join_part::accept(query_part_visitor &visitor)
+{
+  visitor.visit(*this);
+}
+
+void query_on_part::accept(query_part_visitor &visitor)
+{
+  visitor.visit(*this);
+}
+
 void query_where_part::accept(query_part_visitor &visitor)
 {
   visitor.visit(*this);