SQL Query for Parent Child Relationship

Question

I have db table with parent child relationship as:

NodeId    NodeName    ParentId
------------------------------
1         Node1       0
2         Node2              


        

Answer 1

And just to make sure it works if its a parent of itself (otherwise it will recurse until it breaks):

   with [CTE] as (
        select * from [TheTable] c where c.[ParentId] = 1
        union all
        select * from [CTE] p, [TheTable] c where c.[ParentId] = p.[NodeId]
        and c.[ParentId] <> c.[NodeId]
    )
    select * from [CTE]

Answer 2

 WITH Temp_Menu AS
 ( 
  SELECT AM.* from FCB_AccessMenu AM where AM.[ParentId] = 6   

           UNION ALL     

        SELECT AM.* FROM  FCB_AccessMenu AM ,Temp_Menu TM  WHERE AM.[ParentID]=TM.[MenuID]        

  )   

  SELECT * FROM Temp_Menu ORDER BY ParentID

Answer 3

You should look into using the Nested Set Model for parent-child relationships within an SQL database. It's much nicer than trying to store the parentID of records in the table like this, and makes queries like this much easier.

Answer 4

with [CTE] as (
    select * from [TheTable] c where c.[ParentId] = 1
    union all
    select * from [CTE] p, [TheTable] c where c.[ParentId] = p.[NodeId]
)
select * from [CTE]