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 '' 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 id_grupo...') #1 C:\xampp\htdocs\intranet_api\clases\listados_compras.php(61): database->query() #2 C:\xampp\htdocs\intranet_api\compras\listado_compras_proveedores.php(16): listados_compras->crear_json_listado_compras_proveedores(NULL) #3 {main} thrown in C:\xampp\htdocs\intranet_api\database.php on line 75