蚂蚁的:去除重复值如果有ID字段,就是具有唯一性的字段delect table 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
select * into #aa from table group by id1,id2,....
delete table
insert into table
select * from #aa3,没有ID的情况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
col1+','+col2+','...col5 联合主键
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。2,
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...)
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回复人: zzjzhao(风云) ( ) 信誉:100 2003-9-5 8:13:25 得分:10
楼上回答的很全面了
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回复人: pengdali(大力 V2.0) ( ) 信誉:534 2003-9-5 8:19:54 得分:0
删除重复的,只留一条:alter table 表 add newfield int identity(1,1)delete 表
where newfield not in(
select min(newfield) from 表 group by 除newfield外的所有字段
)alter table 表 drop column newfield
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回复人: yujohny(踏网无痕) ( ) 信誉:100 2003-9-5 8:20:04 得分:10
这个问题,肯定有很多人问过,也很多人答过了
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回复人: pengdali(大力 V2.0) ( ) 信誉:534 2003-9-5 8:21:58 得分:20
或:
select distinct * into #temp from 表
truncate table 表
insert 表 select * from #temp
drop table #temp
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回复人: nboys() ( ) 信誉:100 2003-9-5 8:23:47 得分:10
select distinct * into #temp from tableNametruncate table tableNameinsert into tableName select * from #tempdrop table #temp
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回复人: fmdsaco(老小不大) ( ) 信誉:100 2003-9-5 9:30:12 得分:10
use 数据库
alter table 表 add rownum int identity(1,1)
go
delete from 表 where rownum not in (select min(rownum ) from 表group by 重复字段名)
go
alter table 表 drop column rownum
go
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回复人: lusee() ( ) 信誉:100 2003-9-5 11:17:44 得分:0
谢谢各位的帮助!问题解决了!
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如果有ID字段,就是具有唯一性的字段delect table 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
select * into #aa from table group by id1,id2,....
delete table
insert into table
select * from #aa3,没有ID的情况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
col1+','+col2+','...col5 联合主键
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。2,
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...)
where newfield not in(
select min(newfield) from 表 group by equip_name,equip_status
)alter table 表 drop column newfield