progress on record fetch

include/matador/sql/column_generator.hpp

@@ -2,7 +2,6 @@
 #define QUERY_COLUMN_GENERATOR_HPP
 
 #include "matador/sql/column.hpp"
-#include "matador/sql/table_repository.hpp"
 #include "matador/sql/types.hpp"
 
 #include "matador/utils/access.hpp"
@@ -13,6 +12,8 @@
 
 namespace matador::sql {
 
+class table_repository;
+
 class fk_column_generator
 {
 public:

include/matador/sql/connection.hpp

@@ -29,17 +29,23 @@ public:
   [[nodiscard]] bool is_open() const;
   [[nodiscard]] const connection_info& info() const;
 
+  [[nodiscard]] record describe(const std::string &table_name) const;
+
   template<class Type>
   query_result<Type> fetch(const std::string &sql)
   {
-     return query_result<Type>(connection_->execute(sql));
+     return query_result<Type>(connection_->fetch(sql));
   }
-  query_result<record> fetch(const std::string &sql);
-  std::pair<size_t, std::string> execute(const std::string &sql);
+  [[nodiscard]] query_result<record> fetch(const std::string &sql) const;
+  [[nodiscard]] std::pair<size_t, std::string> execute(const std::string &sql) const;
+
+private:
+  friend class session;
+
+  [[nodiscard]] std::unique_ptr<query_result_impl> call_fetch(const std::string &sql) const;
 
 private:
   connection_info connection_info_;
-  bool is_open_{false};
   std::unique_ptr<connection_impl> connection_;
 };
 

include/matador/sql/query_builder.hpp

@@ -54,6 +54,13 @@ enum class join_type_t {
   INNER, OUTER, LEFT, RIGHT
 };
 
+struct query
+{
+  std::string sql;
+  record prototype;
+  std::vector<any_type> host_vars;
+};
+
 class query_builder
 {
 private:
@@ -123,8 +130,6 @@ public:
 
   std::string compile();
 
-  [[nodiscard]] const record& prototype() const;
-
 private:
   void transition_to(state_t next);
   void initialize(command_t cmd, state_t state);
@@ -139,7 +144,7 @@ private:
 
   detail::any_type_to_string_visitor value_to_string_;
 
-  record prototype_;
+  query query_;
 
   using query_state_set = std::unordered_set<state_t>;
   using query_state_transition_map = std::unordered_map<state_t, query_state_set>;

include/matador/sql/query_intermediates.hpp

@@ -47,6 +47,12 @@ protected:
   using query_intermediate::query_intermediate;
 
 public:
+  template < class Type >
+  query_result<Type> fetch_all()
+  {
+    return query_result<Type>(fetch());
+  }
+
   query_result<record> fetch_all();
   record fetch_one();
   template<typename Type>
@@ -55,6 +61,9 @@ public:
     auto result = fetch_all();
     return {};
   }
+
+private:
+  std::unique_ptr<query_result_impl> fetch();
 };
 
 class query_limit_intermediate : public query_select_finish
@@ -124,7 +133,6 @@ public:
   using query_intermediate::query_intermediate;
 
   query_from_intermediate from(const std::string &table, const std::string &as = "");
-
 };
 
 class query_into_intermediate : public query_intermediate
@@ -149,7 +157,7 @@ public:
   template<class Type>
   query_execute_finish table(const std::string &table_name)
   {
-    const auto &info = repository_.attach<Type>(table_name, record{column_generator::generate<Type>(repository_)});
+    const auto &info = repository_.attach<Type>(table_name/*, record{column_generator::generate<Type>(repository_)}*/);
     return {db(), query().table(table_name, info.prototype.columns())};
   }
 

include/matador/sql/query_result.hpp

@@ -115,6 +115,7 @@ public:
 public:
   explicit query_result(std::unique_ptr<query_result_impl> impl)
   : impl_(std::move(impl)) {}
+
   query_result(std::unique_ptr<query_result_impl> impl, creator_func creator)
   : creator_(creator)
   , impl_(std::move(impl)) {}

include/matador/sql/query_result_impl.hpp

@@ -5,6 +5,7 @@
 #include "matador/utils/field_attributes.hpp"
 
 #include "matador/sql/any_type.hpp"
+#include "matador/sql/record.hpp"
 #include "matador/sql/types.hpp"
 
 #include <string>
@@ -16,6 +17,8 @@ class query_result_impl
 public:
   virtual ~query_result_impl() = default;
 
+  virtual size_t column_count() const = 0;
+
   virtual void read_value(const char *id, size_t index, char &value) = 0;
   virtual void read_value(const char *id, size_t index, short &value) = 0;
   virtual void read_value(const char *id, size_t index, int &value) = 0;
@@ -79,8 +82,14 @@ public:
   [[nodiscard]] virtual const char* column(size_t index) const = 0;
   [[nodiscard]] virtual bool fetch() = 0;
 
+  const record& prototype() const;
+
+protected:
+  explicit query_result_impl(record prototype);
+
 protected:
   size_t column_index_ = 0;
+  record prototype_;
 };
 
 }

include/matador/sql/session.hpp

@@ -29,8 +29,8 @@ public:
   query_update_intermediate update(const std::string &table);
   query_delete_intermediate remove();
 
-  query_result<record> fetch(const std::string &sql);
-  std::pair<size_t, std::string> execute(const std::string &sql);
+  [[nodiscard]] query_result<record> fetch(const std::string &sql) const;
+  [[nodiscard]] std::pair<size_t, std::string> execute(const std::string &sql) const;
 
   template<typename Type>
   void attach(const std::string &table_name)
@@ -40,6 +40,11 @@ public:
 
   [[nodiscard]] const table_repository& tables() const;
 
+private:
+  friend class query_select_finish;
+
+  [[nodiscard]] std::unique_ptr<query_result_impl> call_fetch(const std::string &sql) const;
+
 private:
   connection_pool<connection> &pool_;
   query_builder query_;

include/matador/sql/table_repository.hpp

@@ -1,6 +1,7 @@
 #ifndef QUERY_TABLE_REPOSITORY_HPP
 #define QUERY_TABLE_REPOSITORY_HPP
 
+#include "matador/sql/column_generator.hpp"
 #include "matador/sql/record.hpp"
 
 #include <optional>
@@ -20,12 +21,11 @@ class table_repository
 {
 public:
   template<typename Type>
-  const table_info& attach(const std::string &table_name, const record &proto)
+  const table_info& attach(const std::string &table_name)
   {
-    return attach(std::type_index(typeid(Type)), table_name, proto);
+    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 std::string &table_name, const record &proto);
   const table_info& attach(std::type_index ti, const table_info& table);
 
   template<typename Type>