Error: SELECT nombre_subcategoria, nombre_categoria, img_categoria, img_subcategoria FROM categoria LEFT JOIN subcategoria USING (id_categoria) WHERE categoria.id_categoria=index.php AND (subcategoria.id_subcategoria= OR subcategoria.id_subcategoria IS NULL) en la linea <b>20</b> de <b>/home/suminan/public_html/cdp/catalogo.php</b>.<br>MySQL dice: 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 'OR subcategoria.id_subcategoria IS NULL)' at line 1