That's brilliant, thanks Joel! I had discovered the derived table functionality and was stumbling my way through it! You however have helped clarify it for me. Thank you!

And thank you...

Hi Ray, thank you very much for having a look into this.

The database structure can be created thus:

CREATE TABLE [Live].[T1](

 [db1] [varchar](12) COLLATE Latin1_General_CI_AS NULL,

 [tc1] [varchar](20) COLLATE Latin1_General_CI_AS...