Beth,
First, you can avoid the issue by setting ENGINEBEHAVIOR TO 70. That way, existing VFP6 queries should run OK in VFP8.
But to answer your question...what this means is that if you're using a GROUP BY, any columns in your SELECT statement that are not aggregated (i.e. SUMMARIZED) must be included in the group by.
So if you had...
SELECT SSN, FirstName, lastname, SUM(checkamt) from
GROUP BY SSN
That will not work in VFP8, because all non-aggregate columns (columns you're not summarizing...ssn, firstname, lastname) must be included in the group by...
The correct syntax would be
SELECT SSN, FirstName, lastname, SUM(checkamt) from GROUP BY SSN, FIRSTNAME, LASTNAME
Again, if you SET ENGINEBEHAVIOR TO 70, you don't need to change your queries. Having said that, the 1st example will never work in SQL Server, and I generally recommend coding the same way (just my opinion).
Hope that helps,
Kevin