delete all the child rows in sql table by parentid

Question

I have a table from which I create a tree with multiple levels and parents. The table structure looks like this.

When I delete the "TitleID", I want all the children and even the grandchildren to be deleted. What is the easiest way to do such in sql. If I simple delete with "where ParentID=TitleID", only children with level 1 depth are deleted.

Answer 1

DECLARE @TitleId INT 

SELECT @@TitleId = 2 

;WITH results AS( 
        SELECT  TitleId
        FROM    myTable 
        WHERE   TitleId = @TitleId 
        UNION ALL 
        SELECT  t.TitleId 
        FROM    myTable t 
                INNER JOIN ret r ON t.ParentID = r.TitleId
) 

DELETE FROM myTable WHERE TitleId IN (SELECT TitleId FROM    results )