1。查找全部重复记录
代码如下 复制代码
select * from 表 where 重复字段 in (select 重复字段 from 表 group by 重复字段 having count(*)>1)
2。过滤重复记录(只显示一条)
代码如下 复制代码
select * from hzt where id in (select max(id) from hzt group by title)
注：此处显示id最大一条记录
sql server删除重复行是我们最常见的操作之一，下面就为您介绍六种适合不同情况的sql server删除重复行的方法，供您参考。
1.如果有id字段，就是具有唯一性的字段
代码如下 复制代码
delect table tablename where id not in ( select max(id) from table group by col1,col2,col3... )
group by 子句后跟的字段就是你用来判断重复的条件，如只有col1，那么只要col1字段内容相同即表示记录相同。
2. 如果是判断所有字段也可以这样 ，【对于表中的指定的字段的进行检查是否相同】
代码如下 复制代码
select * into #temp from tablename group by id1,id2,....
delete tablename
insert into table select * from #temp
drop table #temp
3. 首先去重复，再获取n*1条数据插入到临时表中，【对于表中的所有字段的进行检查是否相同】，再将原表的数据删除，然后将临时表的数据插入到原表，最后删除临时表。
代码如下 复制代码
select distinct * into #temp from tablename
delete tablename
go
insert tablename select * from #temp
go
drop table #temp
4. 没有id的情况
代码如下 复制代码
select identity(int,1,1) as id,* into #temp from tabel
delect # where id not in (
select max(id) from # group by col1,col2,col3...)
delect table
inset into table(...)
select ..... from #temp
5. col1+','+col2+','...col5 联合主键
代码如下 复制代码
select * from table where col1+','+col2+','...col5 in (
select max(col1+','+col2+','...col5) from table
where having count(*)>1
group by col1,col2,col3,col4
)
group by 子句后跟的字段就是你用来判断重复的条件，如只有col1，那么只要col1字段内容相同即表示记录相同。
6.
代码如下 复制代码
select identity(int,1,1) as id,* into #temp from tabel
select * from #temp where id in (
select max(id) from #emp where having count(*)>1 group by col1,col2,col3...)
其它方法补充
1。删除全部重复记录（慎用）
代码如下 复制代码
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 ^_^）
代码如下 复制代码
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
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
代码如下 复制代码
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
代码如下 复制代码
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）
代码如下 复制代码
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
代码如下 复制代码
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
代码如下 复制代码
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)