The ID's are values of 0's, NULLs or greater than 0. Nonetheless it's a good point.

Thank you very much Antares! That's exactly what I was looking for. Although the performance is effected by this query, I will deal with this in time. Thanks again everyone...

Ok - folks. I tried but it didnt give me the results I was looking for. Let me give you better and detailed example.

Table1

SecondaryID PrimaryID

23432423    |   234

32432432    |  NULL

12123321   ...

Thank you for the suggestions folks. I will give these a try.