Fatal error: Uncaught mysqli_sql_exception: You have an error in your SQL syntax; check the manual that corresponds to your MariaDB server version for the right syntax to use near ') AND ((ventas.anio)='') AND ((ventas.id_venta_tipo)=)) GROUP BY articulos_n....' at line 1 in C:\xampp\htdocs\intranet_api\database.php:75 Stack trace: #0 C:\xampp\htdocs\intranet_api\database.php(75): mysqli_query(Object(mysqli), 'SELECT articulo...') #1 C:\xampp\htdocs\intranet_api\clases\ventas.php(928): database->query() #2 C:\xampp\htdocs\intranet_api\ventas\listado_ventas_articulos.php(15): ventas->crear_json_ventas_articulos(NULL, NULL, NULL) #3 {main} thrown in C:\xampp\htdocs\intranet_api\database.php on line 75