法一: 用Group by语句 此查找很快的select count(num), max(name) from student –查找表中num列重复的，列出重复的记录数，并列出他的name属性group by numhaving count(num) >;1 –按num分组后找出表中num列重复，即出现次数大于一次delete from student(上面Select的)这样的话就把所有重复的都删除了。—–慎重法二:当表比较大(例如10万条以上)时,这个方法的效率之差令人无法忍受,需要另想办法:—- 执行下面SQL语句后就可以显示所有DRAWING和DSNO相同且重复的记录SELECT * FROM EM5_PIPE_PREFABWHERE ROWID!=(SELECT MAX(ROWID) FROM EM5_PIPE_PREFAB D –D相当于First,SecondWHERE EM5_PIPE_PREFAB.DRAWING=D.DRAWING ANDEM5_PIPE_PREFAB.DSNO=D.DSNO);—- 执行下面SQL语句后就可以删除所有DRAWING和DSNO相同且重复的记录DELETE FROM EM5_PIPE_PREFABWHERE ROWID!=(SELECT MAX(ROWID) FROM EM5_PIPE_PREFAB DWHERE EM5_PIPE_PREFAB.DRAWING=D.DRAWING ANDEM5_PIPE_PREFAB.DSNO=D.DSNO);法一: 用Group by语句 此查找很快的select count(num), max(name) from student –查找表中num列重复的，列出重复的记录数，并列出他的name属性group by numhaving count(num) >;1 –按num分组后找出表中num列重复，即出现次数大于一次delete from student(上面Select的)这样的话就把所有重复的都删除了。—–慎重法二:当表比较大(例如10万条以上)时,这个方法的效率之差令人无法忍受,需要另想办法:—- 执行下面SQL语句后就可以显示所有DRAWING和DSNO相同且重复的记录SELECT * FROM EM5_PIPE_PREFABWHERE ROWID!=(SELECT MAX(ROWID) FROM EM5_PIPE_PREFAB D –D相当于First,SecondWHERE EM5_PIPE_PREFAB.DRAWING=D.DRAWING ANDEM5_PIPE_PREFAB.DSNO=D.DSNO);—- 执行下面SQL语句后就可以删除所有DRAWING和DSNO相同且重复的记录DELETE FROM EM5_PIPE_PREFABWHERE ROWID!=(SELECT MAX(ROWID) FROM EM5_PIPE_PREFAB DWHERE EM5_PIPE_PREFAB.DRAWING=D.DRAWING ANDEM5_PIPE_PREFAB.DSNO=D.DSNO);

实现方式如下： Dim cnn As Object, rs As Object, SQL$, i&, s$ Set cnn = CreateObject("ADODB.Connection") cnn.Open "Provider=Microsoft.Jet.Oledb.4.0;data Source=" & ThisWorkbook.Path & "\排课数据.mdb" SQL = "Select 星期&节&班级,count(星期&节&班级) from 排课 where 星期 is not null group by 星期&节&班级 having count(星期&节&班级)>1" Set rs = CreateObject("ADODB.Recordset") rs.Open SQL, cnn, 1, 3 If rs.RecordCount Then For i = 1 To rs.RecordCount s = s & vbCrLf & "星期" & rs.Fields(0) & "班，重复次数：" & rs.Fields(1) rs.MoveNext Next MsgBox "有" & rs.RecordCount & "条记录重复：" & s Else MsgBox "没有发现重复记录" End If rs.Close cnn.Close Set rs = Nothing Set cnn = NothingEnd Sub1。删除全部重复记录（慎用） Delete 表 Where 重复字段 In (Select 重复字段 From 表 Group By 重复字段 Having Count(*)>1)2。保留一条（这个应该是大多数人所需要的 ^_^）Delete HZT Where ID Not In (Select Max(ID) From HZT Group By Title)注：此处保留ID最大一条记录 3、查找表中多余的重复记录（多个字段） select * from vitae awhere (a.peopleId,a.seq) in (select peopleId,seq from vitae group by peopleId,seq having count(*) > 1)4、删除表中多余的重复记录（多个字段），只留有rowid最小的记录delete from vitae awhere (a.peopleId,a.seq) in (select peopleId,seq from vitae group by peopleId,seq having count(*) > 1)and rowid not in (select min(rowid) from vitae group by peopleId,seq having count(*)>1)