(SELECT *, 1 as orden_grupo FROM prod_items WHERE activo_item = 1 AND idcate = ORDER BY RAND() LIMIT 1)
UNION ALL
(SELECT *, 2 as orden_grupo FROM prod_items WHERE activo_item = 1 AND idcate IN (1,2,3,4) ORDER BY RAND() LIMIT 3)
ORDER BY orden_grupo, RAND()
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 'ORDER BY RAND() LIMIT 1)
UNION ALL
(SELECT *, 2 as orden_grupo F' at line 1
#1 /home/carniceriarivas/www/modulos/productos-listado/mod-productos-listado.php(53): WA_MySQLi_RS->execute()
#2 /home/carniceriarivas/www/productosdir/producto-detalle.php(166): require('/home/carniceri...')