ALTER TABLE number ADD 班编号 int nulldeclare @a int,@b varchar(10)
set @a=1
update number set @a=case when class=@b then @a+1 else 1 end,@b=班编号,班编号=@a
set @a=1
update number set @a=case when class=@b then @a+1 else 1 end,@b=班编号,班编号=@a
SchoolId
ClassId
StudentId
这样不是清楚些嘛大力已经解决了
不过你的设计还需改进,表述起来不是很清晰
from Number AA
left join
(select class,min(cast(idschool as int)) as minId from number group by class)BB
on aa.class = bb.class