But what about this? It returns null in both cases....

declare @t int

select case when @t is null then @t else null end

Thanks,

My problem is a bit more complex, I thought about this concatenation-solution but actually this colB is not one column but several columns. I could still concatenate the values into...

Hi, Cool stuff this CTE, but I have a question about the example.

Suppose I want to return not only the leaf-to-parent relation, but also any subparent-to-parent? For example, b ->...

Thanks. One comment:

while (@intCounter <= @intMaxId) should be

while (@intCounter < @intMaxId).