renamed foreign class to entity, introduced interface class query_result_reader

backends/sqlite/include/sqlite_connection.hpp

@@ -14,6 +14,8 @@
 
 #include "matador/sql/connection_impl.hpp"
 
+#include "sqlite_result_reader.hpp"
+
 #include <sqlite3.h>
 
 namespace matador::backends::sqlite {
@@ -35,9 +37,18 @@ public:
 
   bool exists(const std::string &table_name) override;
 
+private:
+  struct fetch_context
+  {
+    sql::record prototype;
+    sqlite_result_reader::rows rows;
+  };
+
 private:
   static int parse_result(void* param, int column_count, char** values, char** columns);
 
+  fetch_context fetch_internal(const std::string &stmt);
+
 private:
   sqlite3 *sqlite_db_{};
 };

backends/sqlite/include/sqlite_result_reader.hpp

@@ -1,24 +1,27 @@
-#ifndef QUERY_SQLITE_QUERY_RESULT_HPP
-#define QUERY_SQLITE_QUERY_RESULT_HPP
+#ifndef QUERY_SQLITE_RESULT_READER_HPP
+#define QUERY_SQLITE_RESULT_READER_HPP
 
-#include "matador/sql/query_result_impl.hpp"
-#include "matador/sql/record.hpp"
+#include "matador/sql/query_result_reader.hpp"
 
 #include <vector>
 
 namespace matador::backends::sqlite {
 
-class sqlite_query_result : public sql::query_result_impl {
+class sqlite_result_reader : public sql::query_result_reader
+{
 public:
   using columns = std::vector<char*>;
   using rows = std::vector<columns>;
 
 public:
-  sqlite_query_result(sql::record prototype, rows result);
-  ~sqlite_query_result() override;
+  sqlite_result_reader(rows result, size_t column_count);
+  ~sqlite_result_reader() override;
 
   size_t column_count() const override;
 
+  [[nodiscard]] const char* column(size_t index) const override;
+  [[nodiscard]] bool fetch() override;
+
   void read_value(const char *id, size_t index, char &value) override;
   void read_value(const char *id, size_t index, short &value) override;
   void read_value(const char *id, size_t index, int &value) override;
@@ -37,20 +40,12 @@ public:
   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;
 
-  [[nodiscard]] const char* column(size_t index) const override;
-  [[nodiscard]] bool fetch() override;
-
-private:
-  friend class sqlite_connection;
-
-private:
-  void push_back(char **row_values, int column_count);
-
 private:
   rows result_;
   long long row_index_ = -1;
+  size_t column_count_{};
 };
 
 }
 
-#endif //QUERY_SQLITE_QUERY_RESULT_HPP
+#endif //QUERY_SQLITE_RESULT_READER_HPP