举例：有两个字段，在相同category下，ID实现自动增长
ID category
1 a
2 a
3 a
1 b
2 b
1 c
如何实现以上的效果？求高手指教！
------解决方案--------------------
select id=row_number() over(partition by category order by getdate()),
category
from tb
------解决方案--------------------
- SQL code
--2000select id0=identity(int,1,1),*into #t from tb select id=(select count(1)+1 from #t where id0<t.id0 and category=t.category),categoryfrom #t t drop table #t