目的:查询一张表的相同的两条数据,并删除一条数据. 分析 先查询出相同的数据,然后删除 查询相同的数据 SELECT a.id FROM account a GROUP BY a.username HAVING COUNT(a.username)>1: DELETE FROM account WHERE id = (SELECT a.id FROM account a GROUP BY a.username HAVING COUNT(a.username)>1) : 1093 - You ca…