Peter,

The IDENTITY field doesn't allow nulls so it wouldn't work for you.

>
>One of the problems is, that in the existing system invoice #'s are assigned at print time, i.e. the records are inserted with an invoice # of null, and records with null values do exist in the client's data.
>
>I actually tried to create an identity column, but it won't let me save the table. Other than that it would be a much better solution, because once the stuff is converted to SQL server they're not going back, so it's a one time thing.
>
>I guess I could select the records with null values into a temporary table,
>delete them in the original and then insert them again? That might work.
>
>Any easier solutions?