--找出重复 SELECT a.* FROM emlog_ad a WHERE a.id IN (SELECT b.id id FROM emlog_ad b GROUP BY b.title HAVING count(b.id)>1);
--删除重复留下id最小的 SELECT a.* FROM emlog_ad a WHERE a.id IN (SELECT b.id FROM emlog_ad b GROUP BY b.title HAVING count(b.id)>1) AND a.id NOT IN (SELECT min(c.id) FROM emlog_ad c GROUP BY c.title HAVING count(c.id)>1);
--一句sql把所有AA改为BB,CC改为DD UPDATE emlog_ad a SET a.`status`=( CASE WHEN a.`status` = '1' THEN '11' WHEN a.`status`='2' THEN '22' END );