Hi Tim,

The following excerpt from VFP7 Readme.htm may explain your problem:

"Because there were several instances where SQL SELECT statements could return incorrect result sets in previous versions of Visual FoxPro, several changes were made in Visual FoxPro 7.0. You should verify that your SQL SELECT statements return expected result sets".


>I've discovered a potential issue when trying to run existing VFP6 code in VFP8. In joining two tables, I was looking for records in table A that had no corresponding record in table B. Here is the code in VFP6:

>SELECT cs.* FROM CustSer cs LEFT JOIN Contlist cl ;
>  ON cs.CustSerID = cl.CustSerID ;
>  WHERE cs.CustSerID # cl.CustSerID
>
>This returns an empty result set.  In VFP8, I needed to have it like this:
>
>SELECT cs.* FROM CustSer cs LEFT JOIN ContList cl ;
>  ON cs.CustSerID = cl.CustSerID ;
>  WHERE ISNULL(cl.CustSerID)

>The VFP8 code likewise will not run correctly in VFP6, even though I set ENGINEBEHAVIOR to 70.
>
>I realize I could use a sub-select query, but the time it takes to run is unacceptable (20 minutes).
>
>Has anyone else noted this behavior and whar are my options for migrating to VFP8 with exiting apps?