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...)
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
或: select distinct * into #temp from 表 truncate table 表 insert 表 select * from #temp drop table #temp
select distinct * into #temp from tableNametruncate table tableNameinsert into tableName select * from #tempdrop table #temp
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
)
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 除newfield外的所有字段
)alter table 表 drop column newfield
select distinct * into #temp from 表
truncate table 表
insert 表 select * from #temp
drop table #temp
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