sql 查出一张表中重复的所有记录数据
1.表中有id和name 两个字段，查询出name重复的所有数据
| select * from xi a where (a.username) in (select username from xi group by username having count(*) > 1) |
2、查询出所有数据进行分组之后，和重复数据的重复次数的查询数据，先列下：
| select count(username) as '重复次数',username from xi group by username having count(*)>1 order by username desc |
3、一下为 查看别人的 结果，现列下：查询及删除重复记录的方法大全
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 peoplewhere 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 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) |
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 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) |
(二)
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 |
(三)
方法一
| declare @max integer,@id integerdeclare cur_rows cursor local for select 主字段,count(*) from 表名 group by 主字段 having count(*) >;open cur_rows fetch cur_rows into @id,@maxwhile @@fetch_status=0begin select @max = @max -1 set rowcount @max delete from 表名 where 主字段 = @idfetch cur_rows into @id,@maxendclose cur_rowsset rowcount 0 |
