数据库 发布日期:2024/12/26 浏览次数:1
遇见了表中存在重复的记录的问题,直接写sql删除时最快的,才不要慢慢的复制到excel表中慢慢的人工找呢
如下sql,找出重复的记录,和重复记录中ID值最小的记录(表中ID为自增长)
select MIN(ID) as id, StructSN ,Date,UserID,StarCount,COUNT(StructSN) as c from T_Dor_StructStar where Date >= '20160919' group by StructSN ,Date,UserID,StarCount having COUNT(StructSN) > 1
然后就可以直接删除,基本原理就是,找到重复记录的每一条记录,排除掉重复id最小的记录,删除剩余的重复记录。
delete from T_Dor_StructStar where ID in ( select s.ID from T_Dor_StructStar s, ( select MIN(ID) as id, StructSN ,Date,UserID,StarCount,COUNT(StructSN) as c from T_Dor_StructStar where Date >= '20160919' group by StructSN ,Date,UserID,StarCount having COUNT(StructSN) > 1 )a where a.Date = s.Date and a.StructSN = s.StructSN and a.UserID = s.UserID and a.StarCount = s.StarCount and a.id != s.ID )
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