array(0) { } string(370) "SELECT pt1.catalog_id, pt2.catalog_id AS rel_id, COUNT(1) AS NumInCommon FROM ( SELECT * FROM `l_catalogs_tags` WHERE catalog_id = ) AS pt1 join `l_catalogs_tags` pt2 on pt1.tag_id = pt2.tag_id and pt1.catalog_id < pt2.catalog_id group by pt1.catalog_id, pt2.catalog_id HAVING NumInCommon >= 1 LIMIT 5" PDO Error: SQLSTATE[42000]: Syntax error or access violation: 1064 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 ') AS pt1 join `l_catalogs_tags` pt2 on pt1.tag_id = pt2.tag_id an' at line 6