SQL²éѯÎÊÌâ
±í½á¹¹ÈçÏÂ
Ô±¹¤±àºÅ ÀàÐÍ Ê±¼ä
1 a 2009-3-1
1 a 2009-3-10
1 b 2009-4-1
1 b 2009-4-10
2 a 2009-1-15
2 a 2009-1-1
°´ÕÕÔ±¹¤£¬ÀàÐÍ·Ö×é Ñ¡³ö×î´óµÄʱ¼ä
½á¹ûÈçÏÂ:
Ô±¹¤±àºÅ ÀàÐÍ Ê±¼ä
1 a 2009-3-10
1 b 2009-4-10
2 a 2009-1-15
SQL code:
select Ô±¹¤±àºÅ,ÀàÐÍ,max(ʱ¼ä) as ʱ¼ä
from tb
group by Ô±¹¤±àºÅ,ÀàÐÍ
SQL code:
---²âÊÔÊý¾Ý---
if object_id('[tb]') is not null drop table [tb]
go
create table [tb]([Ô±¹¤±àºÅ] int,[ÀàÐÍ] varchar(1),[ʱ¼ä] datetime)
insert [tb]
select 1,'a','2009-3-1' union all
select 1,'a','2009-3-10' union all
select 1,'b','2009-4-1' union all
select 1,'b','2009-4-10' union all
select 2,'a','2009-1-15' union all
select 2,'a','2009-1-1'
---²éѯ---
select Ô±¹¤±àºÅ,ÀàÐÍ,max(
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