Discuz! Database Error

SELECT a.* FROM common_member_profile a LEFT JOIN common_member_verify b ON b.uid=a.uid LEFT JOIN common_userportrait c ON c.uid=a.uid WHERE a.qyzt=1 AND a.tradekind='机械' AND a.company <>'' AND a.birthprovince='广东省' AND (a.company LIKE '%机械%' OR a.tradekind='机械' OR a.tradeinfo='机械' OR a.tradeall='机械' OR a.mainproducts1='机械' OR a.mainproducts2='机械' OR a.mainproducts3='机械' OR a.mainproducts4='机械' OR a.mainproducts5='机械' OR a.mainproducts6='机械' OR c.portrait LIKE '%机械%') ORDER BY CASE WHEN b.verify3=1 THEN b.verifytime3 END DESC,CASE WHEN b.verify2=1 THEN b.verifytime2 END DESC,CASE WHEN b.verify1=1 THEN b.verifytime END DESC LIMIT 0,15