SQL read to obtain the parent node of a child node

Function

Create Function getchildren (@ ID varchar (20 ))
Returns @ t table (ID varchar (20)
Begin
Insert @ t select subid from tree where parentid = @ ID
While @ rowcount> 0
Insert @ t select a. subid from tree as a inner join @ T as B
On a. parentid = B. ID and A. subid not in (select ID from @ T)
Return
End

 

Function getchildren
Function getparent to obtain the parent node

 

Select Top 8 * From pdt_detail where companysortid = 1 or companysortid in (select * From getchildren (1 ))

Select * From pdt_detail where companysortid in (select * From getchildren (38 ))