I didn't realise there was a third part to the query. The second part returns all of the supersessions (6 rows) of the chosen number, in the PartNo column - so, that looks good.

The third part returns no rows at all.

Edit: Ok, well after having it operate on a live table with 40,000+ part numbers, I can say it works about 30% of the time.

I think columns like this ...

Old No | New No

1080 | 1080FC

1080F | 1080FC

1080FA | 1080FC

1080FB | 1080FC

... seem to throw it a little bit. If you search for 1080, it returns (OriginalPart) 1080, (PartNo) 1080FC, (PNPrior) 1080 and skips the other numbers entirely.

It would probably help if you could see the data in a larger context.

Thanks for your continued help.