你这样说:a b c
-----------
1.2 aaa cc
1.3 cc dd
1.2 uuu yy你要得到什么??a b c
-----------
1.2 aaa cc
1.3 cc dd吗?
-----------
1.2 aaa cc
1.3 cc dd
1.2 uuu yy你要得到什么??a b c
-----------
1.2 aaa cc
1.3 cc dd吗?
解决方案 »
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where id = (select min(id) from 表 where 字段1=a.字段1)没有关键字段id:select id=IDENTITY(int,1,1),* into #temp from 表select 字段1,字段i,字段j from #temp a
where id = (select min(id) from #temp where 字段1=a.字段1)drop table #temp
哈,哈哈,哈哈哈......
FROM 表1
GROUP BY 字段1;
FROM 表1
GROUP BY 字段1
begin tran
create table tb(a varchar(10),b float,c float)insert into tb(a,b,c) values ('1.2',2,23)
insert into tb(a,b,c) values ('1.3',1,23)
insert into tb(a,b,c) values ('1.2',2,13)
insert into tb(a,b,c) values ('1.2',1,23)select a,min(b) as b,min(c) as c
from tb group by a
rollback tran结果:
a b c
---------- ----------------------------------------------------- -------1.2 1.0 13.0
1.3 1.0 23.0
)
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...)