Matt,
Summing NULL values doesn't work well < grin >. Why don't you surround the "SUM(b.Num2)" code with an isnull()

SELECT SUM(a.num1) AS num1, SUM( iif(isnull(b.Num2), 0, b.Num2)) AS num2 ;
........

You might also specify the 'customer' field used in the ORDER and GROUP clauses as a.Customer to make certain there are no NULL values there either.

HTH
Barbara


>I'm getting an error resulting from a SQL statement that worked fine yesterday, but for some reason not today.
>
>The statement is:
>
>SELECT SUM(a.num1) AS num1, SUM(b.Num2) AS num2 ;
> FROM file1 A ;
> LEFT OUTER JOIN ;
> file2 B ;
> ON a.customer = b.customer ;
> ORDER BY customer ;
> GROUP BY customer ;
> INTO CURSOR flipper ;
> NOFILTER
>
>The error reads field 'num2' does not affect NULL values.
>
>Of course this happens when table B doesn't have any matching records for the customer. I've tried SETting NULL ON and OFF - no affect.
>
>Are there any SQL gurus out there that could lend a hand?
>
>Thanks,
>
>-Matt