Display Parent-Child relationship when Parent and Child are stored in same table

Question

I have SQL Server table structure like below:

ID    Name     ParentID
-----------------------
1     Root       NULL
2     Business   1
3     Finance    1
4           


        

Answer 1

I think the following query would work. I've not tested it.

SELECT
ID
, name
, (CASE WHEN parent_name IS NULL THEN '-' ELSE parent_name END)
FROM
RELATIONS
, (SELECT 
parentID
, name AS parent_name
FROM
RELATION) PARENT
WHERE
RELATIONS.parentId = PARENT.parentId

Basically, what I'm doing is doing is choosing parent information, and relating it to each tuple.