select ID,min(字段2),min(字段3)... group by ID...不知道你是不是要这样的
加个自增长ID,作为唯一ID再按有重复字段的ID分组去自增长ID最大或者最小的
是啊,ID同,后面一大串也都同,就是最后两个字段不同.我想不出好办法了.min 或max也没用
select 相同的字段,min(不同的字段)。。 group by 相同的字段
select 相同的字段,min(不同的字段)。。 group by 相同的字段 select top 1 * from 表 where 列名='##'
****************** 删除重复数据(总结) ******************
一、具有主键的情况
I.具有唯一性的字段id(为唯一主键)
delete 用户表 where id not in ( select max(id) from 用户表 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。
II.具有联合主键
假设col1+','+col2+','...col5 为联合主键(找出相同记录) select * from 用户表 where col1+','+col2+','...col5 in ( select max(col1+','+col2+','...col5) from 用户表 group by col1,col2,col3,col4 having count(*)>1 ) 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。
或者: (找出相同记录) select * from 用户表 where exists (select 1 from 用户表 x where 用户表.col1 = x.col1 and 用户表.col2= x.col2 group by x.col1,x.col2 having count(*) >1)
III:判断所有的字段
select * into #aa from 用户表 group by id1,id2,.... delete 用户表 insert into 用户表 select * from #aa
二、没有主键的情况
I.用临时表实现 select identity(int,1,1) as id,* into #temp from 用户表 delete #temp where id not in ( select max(id) from # group by col1,col2,col3... ) delete 用户表 ta inset into ta(...) select ..... from #temp
II.用改变表结构(加一个唯一字段)来实现
alter 用户表 add newfield int identity(1,1) delete 用户表 where newfield not in ( select min(newfield) from 用户表 group by 除newfield外的所有字段 ) alter 用户表 drop column newfield
--根据楼主的要求,这样就可以了 select identity(int,1,1) as autoID, * into #Tmp from tablenameselect min(autoID) as autoID into #Tmp2 from #Tmp group by [ID]truncate table tablename insert tablename select * from #Tmp where autoID in(select autoID from #tmp2)
delele from tbName a where a.rowid < ( select max(b.rowid) from tbName b where a.col1 = b.col2 and a.col2 = b.col2 ............... ) 如果表中所用字段相同,就全部列都要相等
delete from tbName where rowid in ( select arowid from ( select t.rowid as arowid, row_number() over(partition by col1,col2 ... order by t.rowid) as rn from tbName t ) where rn>=2 ) 同理,根据order by 优先选择保留的记录
11 fd 1 4 0 1 0 0 0 1 1 34 2007-01-17 02:02:00 3 NULL NULL
12 fd 1 4 0 1 0 0 0 1 1 34 2007-01-17 02:02:00 3 83 1
13 fd 1 4 0 1 0 0 0 1 1 34 2007-01-17 02:02:00 3 82 0
13 fd 1 4 0 1 0 0 0 1 1 34 2007-01-17 02:02:00 3 85 1
14 fd 1 4 0 1 0 0 0 1 1 34 2007-01-17 02:02:00 3 81 1
15 fd 1 4 0 1 0 0 0 1 1 34 2007-01-17 02:02:00 3 80 1
16 fd 1 4 0 1 0 0 0 1 1 34 2007-01-17 02:02:00 3 NULL NULL
17 fd 1 4 0 1 0 0 0 1 1 34 2007-01-17 02:02:00 3 NULL NULL
-----------------------------
除了ID,其他字段重复吗?
你取出的结果集,难道只取这个ID字段?
如果只要取ID,Distinct没问题。如果还要取其他字段,同一ID其他字段值不同的话,Distinct没用
group by ID...不知道你是不是要这样的
group by 相同的字段
group by 相同的字段
select top 1 * from 表 where 列名='##'
删除重复数据(总结)
******************
一、具有主键的情况
I.具有唯一性的字段id(为唯一主键)
delete 用户表
where id not in
(
select max(id) from 用户表 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。
II.具有联合主键
假设col1+','+col2+','...col5 为联合主键(找出相同记录)
select * from 用户表 where col1+','+col2+','...col5 in
(
select max(col1+','+col2+','...col5) from 用户表
group by col1,col2,col3,col4
having count(*)>1
)
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。
或者:
(找出相同记录)
select * from 用户表 where exists (select 1 from 用户表 x where 用户表.col1 = x.col1 and
用户表.col2= x.col2 group by x.col1,x.col2 having count(*) >1)
III:判断所有的字段
select * into #aa from 用户表 group by id1,id2,....
delete 用户表
insert into 用户表 select * from #aa
二、没有主键的情况
I.用临时表实现 select identity(int,1,1) as id,* into #temp from 用户表
delete #temp
where id not in
(
select max(id) from # group by col1,col2,col3...
)
delete 用户表 ta
inset into ta(...) select ..... from #temp
II.用改变表结构(加一个唯一字段)来实现
alter 用户表 add newfield int identity(1,1)
delete 用户表
where newfield not in
(
select min(newfield) from 用户表 group by 除newfield外的所有字段
)
alter 用户表 drop column newfield
select identity(int,1,1) as autoID, * into #Tmp from tablenameselect min(autoID) as autoID
into #Tmp2
from #Tmp
group by [ID]truncate table tablename
insert tablename select * from #Tmp where autoID in(select autoID from #tmp2)
where a.rowid <
(
select max(b.rowid) from tbName b
where a.col1 = b.col2
and a.col2 = b.col2
...............
)
如果表中所用字段相同,就全部列都要相等
(
select arowid from
(
select
t.rowid as arowid,
row_number() over(partition by col1,col2 ... order by t.rowid) as rn
from tbName t
) where rn>=2
)
同理,根据order by 优先选择保留的记录