SQL server 存储过程 输入一个父节点查出所有的子节点

http://blog.csdn.net/aqgsh/article/details/8493919

declare @pid int;
set @pid =2;

 declare @pid int;
set @pid =2;

with a as(
select * from dbo.T_Category where id=@pid
union all
select c.* from a , dbo.T_Category c where c.ParentId=a.id

)
select * from a