added sql function and alias

backends/sqlite/src/sqlite_query_result.cpp

@@ -270,7 +270,7 @@ void sqlite_query_result::read_value(const char *id, size_t index, sql::any_type
       throw std::logic_error("data type blob not supported");
     }
     case sql::data_type_t::type_unknown: {
-      value = result_[row_index_][index];
+      value = std::string(result_[row_index_][index]);
       break;
     }
   }