用SQL语句,删除掉重复的记录

1、查找表中多余的重复记录,重复记录是根据单个字段(peopleId)来判断
select * from people
where peopleId in (select peopleId from people group by peopleId having count(peopleId) > 1)
2、删除表中多余的重复记录,重复记录是根据单个字段(peopleId)来判断,只留有rowid最小的记录
delete from people
where peopleId in (select peopleId from people group by peopleId having count(peopleId) > 1)
and rowid not in (select min(rowid) from people group by peopleId having count(peopleId )>1)
3、查找表中多余的重复记录(多个字段)
select * from vitae a
where (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 a
where (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)
5、查找表中多余的重复记录(多个字段),不包含rowid最小的记录
select * from vitae a
where (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)
比方说在A表中存在一个字段“name”,而且不同记录之间的“name”值有可能会相同,
现在就是需要查询出在该表中的各记录之间,“name”值存在重复的项;
Select Name,Count(
) From A Group By Name Having Count() > 1
如果还查性别也相同大则如下:
Select Name,sex,Count(
) From A Group By Name,sex Having Count(*) > 1

ps:筛选出指定月,指定日,指定年的方法:

 SELECT * FROM dbo.v_CashmereInBodyDetails WHERE YEAR(c_time)='2010' AND MONTH(c_time)=6 AND DAY(c_time)=8

 筛选出2010年6月8日的数据

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