added sqlite query result and enhanced column generator and value extractor

backends/sqlite/src/sqlite_connection.cpp

@@ -1,8 +1,11 @@
 #include "sqlite_connection.hpp"
 #include "sqlite_error.hpp"
+#include "sqlite_query_result.hpp"
 
 #include <utility>
 
+#include <memory>
+
 namespace matador::backends::sqlite {
 
 sqlite_connection::sqlite_connection(const sql::connection_info &info)
@@ -32,14 +35,37 @@ bool sqlite_connection::is_open()
   return sqlite_db_ != nullptr;
 }
 
-void sqlite_connection::execute(const std::string &stmt)
+int sqlite_connection::parse_result(void* param, int column_count, char** values, char** columns)
 {
+  auto *result = static_cast<sqlite_query_result*>(param);
+  result->push_back(values, column_count);
 
+  return 0;
+}
+
+size_t sqlite_connection::execute(const std::string &stmt)
+{
+  char *errmsg = nullptr;
+  int ret = sqlite3_exec(sqlite_db_, stmt.c_str(), nullptr, nullptr, &errmsg);
+
+  throw_sqlite_error(ret, sqlite_db_, "sqlite", stmt);
+
+  return sqlite3_changes(sqlite_db_);
+}
+
+std::unique_ptr<sql::query_result_impl> sqlite_connection::fetch(const std::string &stmt)
+{
+  auto result = std::make_unique<sqlite_query_result>();
+  char *errmsg = nullptr;
+  int ret = sqlite3_exec(sqlite_db_, stmt.c_str(), parse_result, result.get(), &errmsg);
+
+  throw_sqlite_error(ret, sqlite_db_, "sqlite", stmt);
+
+  return std::move(result);
 }
 
 void sqlite_connection::prepare(const std::string &stmt)
 {
-
 }
 
 }