表:
ID PID CID
1 975F0C73-51AA-4231-9032-2B4942EE63F7 1
2 54FCDABF-E505-47B7-8172-9E107589F53E 1
3 F8086E8F-81C4-411D-B07F-0968171C7872 1
4 E6359FFE-B813-45CF-8C63-11998D5CB990 1
5 022FF0E6-2589-493B-8F1C-0B2B6EE42B29 2
7 7FC95C46-9C06-4BCB-B733-3E30FC6B1E64 2
8 8038289F-F86F-4B0F-947F-5BCEE0102C36 3
9 E9DD1F68-97B1-4EBD-9760-19F36CE65810 3
10 2BB20D3B-D674-482B-A853-C9D34E2F7A18 3想将CID分组并只取出每组第一条记录。
如,得到:
1 975F0C73-51AA-4231-9032-2B4942EE63F7 1
5 022FF0E6-2589-493B-8F1C-0B2B6EE42B29 2
8 8038289F-F86F-4B0F-947F-5BCEE0102C36 3
SQl语句怎么写?
ID PID CID
1 975F0C73-51AA-4231-9032-2B4942EE63F7 1
2 54FCDABF-E505-47B7-8172-9E107589F53E 1
3 F8086E8F-81C4-411D-B07F-0968171C7872 1
4 E6359FFE-B813-45CF-8C63-11998D5CB990 1
5 022FF0E6-2589-493B-8F1C-0B2B6EE42B29 2
7 7FC95C46-9C06-4BCB-B733-3E30FC6B1E64 2
8 8038289F-F86F-4B0F-947F-5BCEE0102C36 3
9 E9DD1F68-97B1-4EBD-9760-19F36CE65810 3
10 2BB20D3B-D674-482B-A853-C9D34E2F7A18 3想将CID分组并只取出每组第一条记录。
如,得到:
1 975F0C73-51AA-4231-9032-2B4942EE63F7 1
5 022FF0E6-2589-493B-8F1C-0B2B6EE42B29 2
8 8038289F-F86F-4B0F-947F-5BCEE0102C36 3
SQl语句怎么写?
where id=(
select top 1 id from tablename
where cid=a.cid
order by id
)
select *
from tablename
where id in
(
select min(id)
from tablename
group by CID
)
insert into @T select 1 ,'975F0C73-51AA-4231-9032-2B4942EE63F7' , 1
union all select 2 ,'54FCDABF-E505-47B7-8172-9E107589F53E' ,1
union all select 3 ,'F8086E8F-81C4-411D-B07F-0968171C7872' ,1
union all select 4 ,'E6359FFE-B813-45CF-8C63-11998D5CB990' ,1
union all select 5 ,'022FF0E6-2589-493B-8F1C-0B2B6EE42B29' ,2
union all select 7 ,'7FC95C46-9C06-4BCB-B733-3E30FC6B1E64' ,2
union all select 8 ,'8038289F-F86F-4B0F-947F-5BCEE0102C36' ,3
union all select 9 ,'E9DD1F68-97B1-4EBD-9760-19F36CE65810' ,3
union all select 10 ,'2BB20D3B-D674-482B-A853-C9D34E2F7A18' ,3select * from @t a where not exists(select 1 from @t where CID=a.CID and ID<a.ID)