implemented prepared statement for postgres and sqlite

src/CMakeLists.txt

@@ -19,7 +19,13 @@ set(SQL_SOURCES
   sql/table_repository.cpp
   sql/any_type_to_visitor.cpp
   sql/query_result.cpp
-  sql/query_result_reader.cpp)
+  sql/query_result_reader.cpp
+  sql/statement_cache.cpp
+  sql/statement_impl.cpp
+  sql/dialect_builder.cpp
+  sql/object_binder.cpp
+  sql/placeholder_generator.cpp
+)
 
 set(SQL_HEADER
   ../include/matador/sql/dialect.hpp
@@ -31,7 +37,6 @@ set(SQL_HEADER
   ../include/matador/sql/condition.hpp
   ../include/matador/sql/connection.hpp
   ../include/matador/sql/query_intermediates.hpp
-  ../include/matador/sql/result.hpp
   ../include/matador/sql/record.hpp
   ../include/matador/sql/query_result.hpp
   ../include/matador/sql/connection_impl.hpp
@@ -50,7 +55,17 @@ set(SQL_HEADER
   ../include/matador/sql/table_repository.hpp
   ../include/matador/sql/any_type_to_visitor.hpp
   ../include/matador/sql/query_result_reader.hpp
-  ../include/matador/sql/to_value.hpp)
+  ../include/matador/sql/to_value.hpp
+  ../include/matador/sql/statement_cache.hpp
+  ../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_binder.hpp
+  ../include/matador/sql/placeholder_generator.hpp
+)
 
 set(UTILS_HEADER
   ../include/matador/utils/field_attributes.hpp

src/sql/condition.cpp

@@ -3,21 +3,21 @@
 namespace matador::sql {
 
 condition<column, placeholder, std::enable_if<true>::type>::condition(const column &fld, basic_condition::operand_t op, const placeholder &val)
-: basic_column_condition(fld, op)
-, value(val)
-{ }
-
-std::string condition<column, placeholder, std::enable_if<true>::type>::evaluate(dialect &d) const {
-  d.add_host_var(field_.name());
-  return d.prepare_identifier(field_.name()) + " " + operand + " " + d.next_placeholder();
-}
-
-condition<column, query>::condition(column col, basic_condition::operand_t op, query &q)
-: basic_column_condition(std::move(col), op)
-, query_(q)
+: basic_column_condition(fld, op), value(val)
 {}
 
-std::string condition<column, query>::evaluate(dialect &d) const {
+std::string condition<column, placeholder, std::enable_if<true>::type>::evaluate(dialect &d, query_context &query) const
+{
+  query.bind_vars.emplace_back(field_.name());
+  return d.prepare_identifier(field_.name()) + " " + operand + " " + d.next_placeholder(query.bind_vars);
+}
+
+condition<column, query_context>::condition(column col, basic_condition::operand_t op, query_context &q)
+: basic_column_condition(std::move(col), op), query_(q)
+{}
+
+std::string condition<column, query_context>::evaluate(dialect &d, query_context &query) const
+{
   std::string result(d.prepare_identifier(field_.name()) + " " + operand + " (");
   result += (")");
   return result;

src/sql/connection.cpp

@@ -88,4 +88,9 @@ std::unique_ptr<query_result_impl> connection::fetch(const std::string &sql) con
   return connection_->fetch(sql);
 }
 
+statement connection::prepare(query_context &&query) const
+{
+  return statement(connection_->prepare(std::move(query)), logger_);
+}
+
 }

src/sql/dialect.cpp

@@ -5,25 +5,6 @@
 
 namespace matador::sql {
 
-dialect::dialect(const dialect::token_to_string_map &token_replace_map, const dialect::data_type_to_string_map &data_type_replace_map)
-{
-  for (const auto &token : token_replace_map) {
-    tokens_[token.first] = token.second;
-  }
-
-  for (const auto &data_type : data_type_replace_map) {
-    data_types_[data_type.first] = data_type.second;
-  }
-}
-
-dialect::dialect(const dialect::data_type_to_string_map &data_type_replace_map)
-: dialect({}, data_type_replace_map)
-{}
-
-dialect::dialect(const dialect::token_to_string_map &token_replace_map)
-: dialect(token_replace_map, {})
-{}
-
 const std::string& dialect::token_at(dialect::token_t token) const
 {
   return tokens_.at(token);
@@ -85,29 +66,14 @@ dialect::escape_identifier_t dialect::identifier_escape_type() const
   return dialect::escape_identifier_t::ESCAPE_BOTH_SAME;
 }
 
-std::string dialect::next_placeholder() const
+std::string dialect::next_placeholder(const std::vector<std::string> &bind_vars) const
 {
-  return "?";
+  return placeholder_func_(bind_vars.size());
 }
 
-void dialect::add_host_var(const std::string &host_var)
+std::string dialect::default_schema_name() const
 {
-  host_vars_.emplace_back(host_var);
-}
-
-void dialect::add_column(const std::string &column)
-{
-  columns_.emplace_back(column);
-}
-
-const std::vector<std::string> &dialect::host_vars() const
-{
-  return host_vars_;
-}
-
-const std::vector<std::string> &dialect::columns() const
-{
-  return columns_;
+  return default_schema_name_;
 }
 
 }

src/sql/dialect_builder.cpp

@@ -0,0 +1,52 @@
+#include "matador/sql/dialect_builder.hpp"
+
+namespace matador::sql {
+dialect_builder &dialect_builder::builder()
+{
+  static dialect_builder instance;
+  return instance;
+}
+
+dialect_builder &dialect_builder::create()
+{
+  dialect_ = {};
+  return *this;
+}
+
+dialect_builder& dialect_builder::with_token_replace_map(const dialect::token_to_string_map &token_replace_map)
+{
+  for (const auto &token : token_replace_map) {
+    dialect_.tokens_[token.first] = token.second;
+  }
+
+  return *this;
+}
+
+dialect_builder& dialect_builder::with_data_type_replace_map(const dialect::data_type_to_string_map &data_type_replace_map)
+{
+  for (const auto &data_type : data_type_replace_map) {
+    dialect_.data_types_[data_type.first] = data_type.second;
+  }
+
+  return *this;
+}
+
+dialect_builder& dialect_builder::with_placeholder_func(const dialect::next_placeholder_func &func)
+{
+  dialect_.placeholder_func_ = func;
+
+  return *this;
+}
+
+dialect_builder &dialect_builder::with_default_schema_name(const std::string &schema_name)
+{
+  dialect_.default_schema_name_ = schema_name;
+
+  return *this;
+}
+
+dialect dialect_builder::build()
+{
+  return dialect_;
+}
+}

src/sql/object_binder.cpp

@@ -0,0 +1,24 @@
+#include "matador/sql/object_binder.hpp"
+#include "matador/sql/parameter_binder.hpp"
+
+namespace matador::sql {
+
+object_binder::object_binder(parameter_binder &binder)
+: binder_(binder) {}
+
+void object_binder::reset()
+{
+  index_ = 0;
+}
+
+void object_binder::on_primary_key(const char *id, std::string &val, size_t)
+{
+  binder_.bind(index_++, val);
+}
+
+void object_binder::on_revision(const char *id, unsigned long long int &rev)
+{
+  binder_.bind(index_++, rev);
+}
+
+}

src/sql/placeholder_generator.cpp

@@ -0,0 +1,15 @@
+#include "matador/sql/placeholder_generator.hpp"
+
+namespace matador::sql {
+
+void placeholder_generator::on_primary_key(const char *id, std::string &, size_t)
+{
+  placeholder_values.emplace_back(_);
+}
+
+void placeholder_generator::on_revision(const char *id, unsigned long long int &)
+{
+  placeholder_values.emplace_back(_);
+}
+
+}

src/sql/query_builder.cpp

@@ -9,6 +9,9 @@ namespace matador::sql {
 
 namespace detail {
 
+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) + "'";
@@ -19,69 +22,76 @@ void any_type_to_string_visitor::to_string(std::string &val)
   result = "'" + d.prepare_literal(val) + "'";
 }
 
+void any_type_to_string_visitor::to_string(placeholder &/*val*/)
+{
+  query.bind_vars.emplace_back("unknown");
+  result = d.next_placeholder(query.bind_vars);
+}
+
 }
 
 // poor mens state machine
 // but does the job for query
 query_builder::query_state_transition_map query_builder::transitions_{
-  {state_t::QUERY_INIT, {state_t::QUERY_CREATE, state_t::QUERY_DROP, state_t::QUERY_SELECT, state_t::QUERY_INSERT, state_t::QUERY_UPDATE, state_t::QUERY_DELETE}},
-  {state_t::QUERY_CREATE, {state_t::QUERY_TABLE_CREATE}},
-  {state_t::QUERY_DROP, {state_t::QUERY_TABLE_DROP}},
-  {state_t::QUERY_SELECT, {state_t::QUERY_FROM}},
-  {state_t::QUERY_INSERT, {state_t::QUERY_INTO}},
-  {state_t::QUERY_UPDATE, {state_t::QUERY_SET}},
-  {state_t::QUERY_DELETE, {state_t::QUERY_FROM}},
-  {state_t::QUERY_TABLE_CREATE, {state_t::QUERY_FINISH}},
-  {state_t::QUERY_TABLE_DROP, {state_t::QUERY_FINISH}},
-  {state_t::QUERY_FROM, {state_t::QUERY_OFFSET, state_t::QUERY_LIMIT, state_t::QUERY_WHERE, state_t::QUERY_ORDER_BY, state_t::QUERY_GROUP_BY, state_t::QUERY_FINISH}},
-  {state_t::QUERY_SET, {state_t::QUERY_WHERE, state_t::QUERY_FINISH}},
-  {state_t::QUERY_INTO, {state_t::QUERY_VALUES}},
-  {state_t::QUERY_WHERE, {state_t::QUERY_ORDER_BY, state_t::QUERY_GROUP_BY, state_t::QUERY_OFFSET, state_t::QUERY_LIMIT, state_t::QUERY_FINISH}},
-  {state_t::QUERY_ORDER_BY, {state_t::QUERY_ORDER_DIRECTION}},
-  {state_t::QUERY_ORDER_DIRECTION, {state_t::QUERY_OFFSET, state_t::QUERY_LIMIT, state_t::QUERY_FINISH}},
-  {state_t::QUERY_GROUP_BY, {state_t::QUERY_ORDER_BY, state_t::QUERY_FINISH}},
-  {state_t::QUERY_OFFSET, {state_t::QUERY_LIMIT}},
-  {state_t::QUERY_LIMIT, {state_t::QUERY_FINISH}},
-  {state_t::QUERY_VALUES, {state_t::QUERY_FINISH}},
-  {state_t::QUERY_FINISH, {}},
+{state_t::QUERY_INIT,            {state_t::QUERY_CREATE,   state_t::QUERY_DROP,     state_t::QUERY_SELECT, state_t::QUERY_INSERT,   state_t::QUERY_UPDATE,   state_t::QUERY_DELETE}},
+{state_t::QUERY_CREATE,          {state_t::QUERY_TABLE_CREATE}},
+{state_t::QUERY_DROP,            {state_t::QUERY_TABLE_DROP}},
+{state_t::QUERY_SELECT,          {state_t::QUERY_FROM}},
+{state_t::QUERY_INSERT,          {state_t::QUERY_INTO}},
+{state_t::QUERY_UPDATE,          {state_t::QUERY_SET}},
+{state_t::QUERY_DELETE,          {state_t::QUERY_FROM}},
+{state_t::QUERY_TABLE_CREATE,    {state_t::QUERY_FINISH}},
+{state_t::QUERY_TABLE_DROP,      {state_t::QUERY_FINISH}},
+{state_t::QUERY_FROM,            {state_t::QUERY_OFFSET,   state_t::QUERY_LIMIT,    state_t::QUERY_WHERE,  state_t::QUERY_ORDER_BY, state_t::QUERY_GROUP_BY, state_t::QUERY_FINISH}},
+{state_t::QUERY_SET,             {state_t::QUERY_WHERE,    state_t::QUERY_FINISH}},
+{state_t::QUERY_INTO,            {state_t::QUERY_VALUES}},
+{state_t::QUERY_WHERE,           {state_t::QUERY_ORDER_BY, state_t::QUERY_GROUP_BY, state_t::QUERY_OFFSET, state_t::QUERY_LIMIT,    state_t::QUERY_FINISH}},
+{state_t::QUERY_ORDER_BY,        {state_t::QUERY_ORDER_DIRECTION}},
+{state_t::QUERY_ORDER_DIRECTION, {state_t::QUERY_OFFSET,   state_t::QUERY_LIMIT,    state_t::QUERY_FINISH}},
+{state_t::QUERY_GROUP_BY,        {state_t::QUERY_ORDER_BY, state_t::QUERY_FINISH}},
+{state_t::QUERY_OFFSET,          {state_t::QUERY_LIMIT}},
+{state_t::QUERY_LIMIT,           {state_t::QUERY_FINISH}},
+{state_t::QUERY_VALUES,          {state_t::QUERY_FINISH}},
+{state_t::QUERY_FINISH,          {}},
 };
 
-query_builder::query_state_to_string_map query_builder::state_strings_ {
-  { state_t::QUERY_INIT, "init" },
-  { state_t::QUERY_CREATE, "create" },
-  { state_t::QUERY_DROP, "drop" },
-  { state_t::QUERY_SELECT, "select" },
-  { state_t::QUERY_INSERT, "insert" },
-  { state_t::QUERY_UPDATE, "update" },
-  { state_t::QUERY_DELETE, "delete" },
-  { state_t::QUERY_TABLE_CREATE, "table" },
-  { state_t::QUERY_TABLE_DROP, "table" },
-  { state_t::QUERY_FROM, "from" },
-  { state_t::QUERY_SET, "set" },
-  { state_t::QUERY_INTO, "into" },
-  { state_t::QUERY_WHERE, "where" },
-  { state_t::QUERY_ORDER_BY, "order_by" },
-  { state_t::QUERY_GROUP_BY, "group_by" },
-  { state_t::QUERY_OFFSET, "offset" },
-  { state_t::QUERY_LIMIT, "limit" },
-  { state_t::QUERY_FINISH, "finish" },
+query_builder::query_state_to_string_map query_builder::state_strings_{
+{state_t::QUERY_INIT,         "init"},
+{state_t::QUERY_CREATE,       "create"},
+{state_t::QUERY_DROP,         "drop"},
+{state_t::QUERY_SELECT,       "select"},
+{state_t::QUERY_INSERT,       "insert"},
+{state_t::QUERY_UPDATE,       "update"},
+{state_t::QUERY_DELETE,       "delete"},
+{state_t::QUERY_TABLE_CREATE, "table"},
+{state_t::QUERY_TABLE_DROP,   "table"},
+{state_t::QUERY_FROM,         "from"},
+{state_t::QUERY_SET,          "set"},
+{state_t::QUERY_INTO,         "into"},
+{state_t::QUERY_WHERE,        "where"},
+{state_t::QUERY_ORDER_BY,     "order_by"},
+{state_t::QUERY_GROUP_BY,     "group_by"},
+{state_t::QUERY_OFFSET,       "offset"},
+{state_t::QUERY_LIMIT,        "limit"},
+{state_t::QUERY_FINISH,       "finish"},
 };
 
-query_builder::query_command_to_string_map query_builder::command_strings_ {
-  { command_t::UNKNOWN, "unknown" },
-  { command_t::CREATE, "create" },
-  { command_t::DROP, "drop" },
-  { command_t::SELECT, "select" },
-  { command_t::INSERT, "insert" },
-  { command_t::UPDATE, "update" },
-  { command_t::REMOVE, "remove" },
+query_builder::query_command_to_string_map query_builder::command_strings_{
+{command_t::UNKNOWN, "unknown"},
+{command_t::CREATE,  "create"},
+{command_t::DROP,    "drop"},
+{command_t::SELECT,  "select"},
+{command_t::INSERT,  "insert"},
+{command_t::UPDATE,  "update"},
+{command_t::REMOVE,  "remove"},
 };
 
 query_builder::query_builder(const dialect &d)
-: dialect_(d)
-, value_to_string_(d) {}
+: dialect_(d), value_to_string_(d, query_)
+{}
 
-query_builder& query_builder::create() {
+query_builder &query_builder::create()
+{
   initialize(command_t::CREATE, state_t::QUERY_CREATE);
 
   query_parts_.emplace_back(dialect_.token_at(dialect::token_t::CREATE));
@@ -89,7 +99,8 @@ query_builder& query_builder::create() {
   return *this;
 }
 
-query_builder& query_builder::drop() {
+query_builder &query_builder::drop()
+{
   initialize(command_t::DROP, state_t::QUERY_DROP);
 
   query_parts_.emplace_back(dialect_.token_at(dialect::token_t::DROP));
@@ -97,7 +108,7 @@ query_builder& query_builder::drop() {
   return *this;
 }
 
-query_builder& query_builder::select(std::initializer_list<column> columns)
+query_builder &query_builder::select(std::initializer_list<column> columns)
 {
   return select(std::vector<column>{columns});
 }
@@ -112,7 +123,7 @@ query_builder &query_builder::select(const std::vector<column> &columns)
 
   std::string result;
   if (columns.size() < 2) {
-    for (const auto &col : columns) {
+    for (const auto &col: columns) {
       result.append(dialect_.prepare_identifier(col));
       query_.prototype.append(col);
     }
@@ -131,7 +142,8 @@ query_builder &query_builder::select(const std::vector<column> &columns)
   return *this;
 }
 
-query_builder& query_builder::insert() {
+query_builder &query_builder::insert()
+{
   initialize(command_t::INSERT, state_t::QUERY_INSERT);
 
   query_parts_.emplace_back(dialect_.token_at(dialect::token_t::INSERT));
@@ -139,7 +151,8 @@ query_builder& query_builder::insert() {
   return *this;
 }
 
-query_builder& query_builder::update(const std::string &table) {
+query_builder &query_builder::update(const std::string &table)
+{
   initialize(command_t::UPDATE, state_t::QUERY_UPDATE);
 
   query_.table_name = table;
@@ -148,7 +161,8 @@ query_builder& query_builder::update(const std::string &table) {
   return *this;
 }
 
-query_builder& query_builder::remove() {
+query_builder &query_builder::remove()
+{
   initialize(command_t::REMOVE, state_t::QUERY_DELETE);
 
   query_parts_.emplace_back(dialect_.token_at(dialect::token_t::REMOVE));
@@ -156,7 +170,7 @@ query_builder& query_builder::remove() {
   return *this;
 }
 
-query_builder& query_builder::table(const std::string &table, std::initializer_list<column> columns)
+query_builder &query_builder::table(const std::string &table, std::initializer_list<column> columns)
 {
   return this->table(table, std::vector<column>{columns});
 }
@@ -176,7 +190,8 @@ struct column_context
 
 std::string build_create_column(const column &col, const dialect &d, column_context &context);
 
-query_builder &query_builder::table(const std::string &table, const std::vector<column> &columns) {
+query_builder &query_builder::table(const std::string &table, const std::vector<column> &columns)
+{
   transition_to(state_t::QUERY_TABLE_CREATE);
 
   query_parts_.emplace_back(" " + dialect_.token_at(dialect::token_t::TABLE) + " " + dialect_.prepare_identifier(table) + " ");
@@ -187,7 +202,7 @@ query_builder &query_builder::table(const std::string &table, const std::vector<
   column_context context;
 
   if (columns.size() < 2) {
-    for (const auto &col : columns) {
+    for (const auto &col: columns) {
       result.append(build_create_column(col, dialect_, context));
     }
   } else {
@@ -202,7 +217,7 @@ query_builder &query_builder::table(const std::string &table, const std::vector<
   if (!context.primary_keys.empty()) {
     result.append(", CONSTRAINT PK_" + table + " PRIMARY KEY (" + utils::join(context.primary_keys, ", ") + ")");
   }
-  for (const auto &fk : context.foreign_contexts) {
+  for (const auto &fk: context.foreign_contexts) {
     result += ", CONSTRAINT FK_" + table;
     result += "_" + fk.column;
     result += " FOREIGN KEY (" + fk.column + ")";
@@ -214,7 +229,8 @@ query_builder &query_builder::table(const std::string &table, const std::vector<
   return *this;
 }
 
-query_builder& query_builder::table(const std::string &table) {
+query_builder &query_builder::table(const std::string &table)
+{
   transition_to(state_t::QUERY_TABLE_DROP);
 
   query_parts_.emplace_back(" " + dialect_.token_at(dialect::token_t::TABLE) + " " + dialect_.prepare_identifier(table));
@@ -223,7 +239,7 @@ query_builder& query_builder::table(const std::string &table) {
   return *this;
 }
 
-query_builder& query_builder::into(const std::string &table, std::initializer_list<std::string> column_names)
+query_builder &query_builder::into(const std::string &table, std::initializer_list<std::string> column_names)
 {
   return into(table, std::vector<std::string>{column_names});
 }
@@ -237,7 +253,7 @@ query_builder &query_builder::into(const std::string &table, const std::vector<s
 
   std::string result{"("};
   if (column_names.size() < 2) {
-    for (const auto &col : column_names) {
+    for (const auto &col: column_names) {
       result.append(dialect_.prepare_identifier(col));
     }
   } else {
@@ -254,19 +270,20 @@ query_builder &query_builder::into(const std::string &table, const std::vector<s
   return *this;
 }
 
-query_builder& query_builder::values(std::initializer_list<any_type> values)
+query_builder &query_builder::values(std::initializer_list<any_type> values)
 {
   return this->values(std::vector<any_type>{values});
 }
 
-query_builder& query_builder::values(const std::vector<any_type> &values) {
+query_builder &query_builder::values(const std::vector<any_type> &values)
+{
   transition_to(state_t::QUERY_VALUES);
 
   query_parts_.emplace_back(" " + dialect_.token_at(dialect::token_t::VALUES) + " ");
 
   std::string result{"("};
   if (values.size() < 2) {
-    for (auto val : values) {
+    for (auto val: values) {
       query_.host_vars.push_back(val);
       std::visit(value_to_string_, val);
       result.append(value_to_string_.result);
@@ -291,10 +308,20 @@ query_builder& query_builder::values(const std::vector<any_type> &values) {
   return *this;
 }
 
-query_builder& query_builder::from(const std::string &table, const std::string &as) {
+query_builder &query_builder::from(const std::string &table, const std::string &as)
+{
   transition_to(state_t::QUERY_FROM);
 
-  query_parts_.emplace_back(" " + dialect_.token_at(dialect::token_t::FROM) + " " + dialect_.prepare_identifier(table) + (as.empty() ? "" : " " + as));
+  if (dialect_.default_schema_name().empty()) {
+    query_parts_.emplace_back(" " + dialect_.token_at(dialect::token_t::FROM) +
+                              " " + dialect_.prepare_identifier(table) +
+                              (as.empty() ? "" : " " + as));
+  } else {
+    query_parts_.emplace_back(" " + dialect_.token_at(dialect::token_t::FROM) +
+                              " " + dialect_.prepare_identifier(dialect_.default_schema_name()) +
+                              "." + dialect_.prepare_identifier(table) +
+                              (as.empty() ? "" : " " + as));
+  }
   query_.table_name = table;
 
   return *this;
@@ -315,14 +342,15 @@ query_builder &query_builder::set(std::initializer_list<key_value_pair> key_valu
   return set(std::vector<key_value_pair>{key_values});
 }
 
-query_builder& query_builder::set(const std::vector<key_value_pair> &key_values) {
+query_builder &query_builder::set(const std::vector<key_value_pair> &key_values)
+{
   transition_to(state_t::QUERY_SET);
 
   query_parts_.emplace_back(" " + dialect_.token_at(dialect::token_t::SET) + " ");
 
   std::string result;
   if (key_values.size() < 2) {
-    for (const auto &col : key_values) {
+    for (const auto &col: key_values) {
       result.append(dialect_.prepare_identifier(col.name()) + "=");
       auto var = col.value();
       std::visit(value_to_string_, var);
@@ -347,67 +375,76 @@ query_builder& query_builder::set(const std::vector<key_value_pair> &key_values)
   return *this;
 }
 
-query_builder& query_builder::where(const basic_condition &cond) {
+query_builder &query_builder::where(const basic_condition &cond)
+{
   transition_to(state_t::QUERY_WHERE);
 
   query_parts_.emplace_back(" " + dialect_.token_at(dialect::token_t::WHERE) + " ");
-  query_parts_.emplace_back(cond.evaluate(const_cast<dialect &>(dialect_)));
+  query_parts_.emplace_back(cond.evaluate(const_cast<dialect &>(dialect_), query_));
 
   return *this;
 }
 
-query_builder& query_builder::order_by(const std::string& column) {
-    transition_to(state_t::QUERY_ORDER_BY);
+query_builder &query_builder::order_by(const std::string &column)
+{
+  transition_to(state_t::QUERY_ORDER_BY);
 
-    query_parts_.emplace_back(" " + dialect_.token_at(dialect::token_t::ORDER_BY) + " " + dialect_.prepare_identifier(column));
+  query_parts_.emplace_back(" " + dialect_.token_at(dialect::token_t::ORDER_BY) + " " + dialect_.prepare_identifier(column));
 
-    return *this;
+  return *this;
 }
 
-query_builder& query_builder::group_by(const std::string& column) {
-    transition_to(state_t::QUERY_GROUP_BY);
+query_builder &query_builder::group_by(const std::string &column)
+{
+  transition_to(state_t::QUERY_GROUP_BY);
 
-    query_parts_.emplace_back(" " + dialect_.token_at(dialect::token_t::GROUP_BY) + " " + dialect_.prepare_identifier(column));
+  query_parts_.emplace_back(" " + dialect_.token_at(dialect::token_t::GROUP_BY) + " " + dialect_.prepare_identifier(column));
 
-    return *this;
+  return *this;
 }
 
-query_builder& query_builder::asc() {
-    transition_to(state_t::QUERY_ORDER_DIRECTION);
+query_builder &query_builder::asc()
+{
+  transition_to(state_t::QUERY_ORDER_DIRECTION);
 
-    query_parts_.emplace_back(" " + dialect_.token_at(dialect::token_t::ASC));
+  query_parts_.emplace_back(" " + dialect_.token_at(dialect::token_t::ASC));
 
-    return *this;
+  return *this;
 }
 
-query_builder& query_builder::desc() {
-    transition_to(state_t::QUERY_ORDER_DIRECTION);
+query_builder &query_builder::desc()
+{
+  transition_to(state_t::QUERY_ORDER_DIRECTION);
 
-    query_parts_.emplace_back(" " + dialect_.token_at(dialect::token_t::DESC));
+  query_parts_.emplace_back(" " + dialect_.token_at(dialect::token_t::DESC));
 
-    return *this;
+  return *this;
 }
 
-query_builder& query_builder::offset( size_t count ) {
-    transition_to(state_t::QUERY_OFFSET);
+query_builder &query_builder::offset(size_t count)
+{
+  transition_to(state_t::QUERY_OFFSET);
 
-    query_parts_.emplace_back(" " + dialect_.token_at(dialect::token_t::OFFSET) + " " + std::to_string(count));
+  query_parts_.emplace_back(" " + dialect_.token_at(dialect::token_t::OFFSET) + " " + std::to_string(count));
 
-    return *this;
+  return *this;
 }
 
-query_builder& query_builder::limit( size_t count ) {
-    transition_to(state_t::QUERY_LIMIT);
+query_builder &query_builder::limit(size_t count)
+{
+  transition_to(state_t::QUERY_LIMIT);
 
-    query_parts_.emplace_back( " " + dialect_.token_at(dialect::token_t::LIMIT) + " " + std::to_string( count));
+  query_parts_.emplace_back(" " + dialect_.token_at(dialect::token_t::LIMIT) + " " + std::to_string(count));
 
-    return *this;
+  return *this;
 }
 
-query query_builder::compile() {
-  for (const auto &part : query_parts_) {
+query_context query_builder::compile()
+{
+  for (const auto &part: query_parts_) {
     query_.sql.append(part);
   }
+  query_.command_name = command_strings_[command_];
   return query_;
 }
 
@@ -427,22 +464,23 @@ void query_builder::initialize(query_builder::command_t cmd, query_builder::stat
   query_parts_.clear();
 }
 
-std::string build_create_column(const column &col, const dialect &d, column_context &context) {
-    std::string result = d.prepare_identifier(col.name()) + " " + d.data_type_at(col.type());
-    if (col.attributes().size() > 0) {
-        result.append("(" + std::to_string(col.attributes().size()) +")");
-    }
-    if (is_constraint_set(col.attributes().options(), utils::constraints::NOT_NULL)) {
-        result.append(" NOT NULL");
-    }
-    if (is_constraint_set(col.attributes().options(), utils::constraints::PRIMARY_KEY)) {
-        context.primary_keys.emplace_back(col.name());
-    }
-    if (is_constraint_set(col.attributes().options(), utils::constraints::FOREIGN_KEY)) {
-        context.foreign_contexts.push_back({col.name(), col.ref_table(), col.ref_column()});
-    }
+std::string build_create_column(const column &col, const dialect &d, column_context &context)
+{
+  std::string result = d.prepare_identifier(col.name()) + " " + d.data_type_at(col.type());
+  if (col.attributes().size() > 0) {
+    result.append("(" + std::to_string(col.attributes().size()) + ")");
+  }
+  if (is_constraint_set(col.attributes().options(), utils::constraints::NOT_NULL)) {
+    result.append(" NOT NULL");
+  }
+  if (is_constraint_set(col.attributes().options(), utils::constraints::PRIMARY_KEY)) {
+    context.primary_keys.emplace_back(col.name());
+  }
+  if (is_constraint_set(col.attributes().options(), utils::constraints::FOREIGN_KEY)) {
+    context.foreign_contexts.push_back({col.name(), col.ref_table(), col.ref_column()});
+  }
 
-    return result;
+  return result;
 }
 
 column alias(const std::string &column, const std::string &as)
@@ -450,7 +488,8 @@ column alias(const std::string &column, const std::string &as)
   return {column, as};
 }
 
-column alias(column &&col, const std::string &as) {
+column alias(column &&col, const std::string &as)
+{
   col.alias(as);
   return std::move(col);
 }

src/sql/query_intermediates.cpp

@@ -18,6 +18,11 @@ std::unique_ptr<query_result_impl> query_select_finish::fetch()
   return session_.fetch(builder_.compile().sql);
 }
 
+statement query_select_finish::prepare()
+{
+  return session_.prepare(builder_.compile());
+}
+
 query_intermediate::query_intermediate(session &db, query_builder &query)
 : session_(db), builder_(query) {}
 
@@ -103,6 +108,11 @@ std::pair<size_t, std::string> query_execute_finish::execute()
   return session_.execute(builder_.compile().sql);
 }
 
+statement query_execute_finish::prepare()
+{
+  return session_.prepare(builder_.compile());
+}
+
 query_execute_finish query_into_intermediate::values(std::initializer_list<any_type> values)
 {
   return {session_, builder_.values(values)};
@@ -140,10 +150,10 @@ query_execute_where_intermediate query_set_intermediate::where(const basic_condi
   return {session_, builder_.where(cond)};
 }
 
-query_update_intermediate::query_update_intermediate(session &s, std::string table_name)
+query_update_intermediate::query_update_intermediate(session &s, const std::string& table_name)
 : query_start_intermediate(s)
 {
-  builder_.update(std::move(table_name));
+  builder_.update(table_name);
 }
 
 query_set_intermediate query_update_intermediate::set(std::initializer_list<key_value_pair> columns)

src/sql/session.cpp

@@ -40,7 +40,7 @@ query_delete_intermediate session::remove()
   return query_delete_intermediate{*this};
 }
 
-query_result<record> session::fetch(const query &q) const
+query_result<record> session::fetch(const query_context &q) const
 {
   auto c = pool_.acquire();
   if (!c.valid()) {
@@ -73,6 +73,15 @@ std::pair<size_t, std::string> session::execute(const std::string &sql) const {
   return c->execute(sql);
 }
 
+statement session::prepare(query_context q) const
+{
+  auto c = pool_.acquire();
+  if (!c.valid()) {
+    throw std::logic_error("no database connection available");
+  }
+  return c->prepare(std::move(q));
+}
+
 record session::describe_table(const std::string &table_name) const
 {
   auto c = pool_.acquire();

src/sql/statement.cpp

@@ -0,0 +1,34 @@
+#include "matador/sql/statement.hpp"
+
+namespace matador::sql {
+
+statement::statement(std::unique_ptr<statement_impl> impl, const utils::logger &logger)
+: statement_(std::move(impl))
+, logger_(logger)
+, object_binder_(statement_->binder())
+{}
+
+statement &statement::bind(size_t pos, std::string &val, size_t size)
+{
+  statement_->bind(pos, val, size);
+  return *this;
+}
+
+size_t statement::execute()
+{
+  logger_.info(statement_->query_.sql);
+  return statement_->execute();
+}
+
+query_result<record> statement::fetch()
+{
+  logger_.info(statement_->query_.sql);
+  return query_result<record>(statement_->fetch());
+}
+
+void statement::reset()
+{
+  statement_->reset();
+}
+
+}

src/sql/statement_cache.cpp

@@ -0,0 +1,17 @@
+#include "matador/sql/statement_cache.hpp"
+
+namespace matador::sql {
+statement &statement_cache::acquire(const std::string &stmt, const connection &conn) {
+  std::lock_guard<std::mutex> guard(mutex_);
+  auto key = hash_(stmt);
+  auto it = statement_map_.find(key);
+  if (it == statement_map_.end()) {
+
+  }
+  return *it->second.statement_;
+}
+
+void statement_cache::release(const statement &stmt) {
+
+}
+}

src/sql/statement_impl.cpp

@@ -0,0 +1,9 @@
+#include "matador/sql/statement_impl.hpp"
+
+namespace matador::sql {
+
+statement_impl::statement_impl(query_context query)
+: query_(std::move(query))
+{}
+
+}