自查询一例：求连续出现的次数

数据表如下：

代码

select * from tb

select identity(int,1,1) as id,*
into #db
from tb

select * from #db

select a.value1,a.value2,nums=(
select count(1) from #db where value1=a.value1
and id<=a.id
and id>=(select isnull(max(id),0) from #db where id<a.id and value1 !=a.value1)
)
from #db as a

drop table #db

结果如下：