Primary Key Help

[Alex]

I have a .txt file that is imported into my db each month, which contains the
following fields:

Desk RcdLoc

Each record represents a person. Each person has either a Desk or RcdLoc
code assinged to them. A person can sometimes have both.

I really need to have a primary key in this table. I know I can't do a
multiple primary key because most of the time either Desk or RcdLoc is null.

I know that if I were creating these records from a form or in the table, an
autonumber field could be the primary key, but will and how would an
Autonumber field work with the imported .txt file?

Thanks for you help

 

[KARL DEWEY]

If you set the Default to "-" then it will not be null.

 

[Alex]

I created a primary key by adding an autonumber field to the Main table,
importing the New table then appending the Main table with records from New
table. This works great. Thanks