Now that's really interesting!!..
I've decided to go with the WHERE NOT IN (SELECT....) construct, eventhough its not optimizable when comparing multiple fields (unless an index exists with the exact expression). However, I like your solution a LOT better than using the HAVING clause. The having clause gets tricky when you have GROUP BY's. Thanks a lot for your info Peter!!
Mark

>Mark,
>I got the same reults with your sample.
>But if I just add =.T. at the end it works fine in VFP7 as expected,
>no matter if its indexed or not.
>
>

>SELECT tbl1.*;
>FROM tbl1;
>LEFT JOIN tbl2;
>ON;
>tbl1.userid = tbl2.userid;
>WHERE;
>ISNULL(tbl2.userid) = .T.
>

>
>Peter