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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