Are all SQL Selects legal in VFP8? If not, is there a list somewhere of what works?

For example, this Select statement that compares data tables, works in SQL 2000 but does not work in VFP6:

select custnum, firstname
FROM
(
SELECT 'cust' as table, custnum, firstname
FROM cust
UNION ALL
SELECT 'cust_dupe' as table, custnum, firstname
FROM cust_dupe
)
GROUP BY custnum, firstname
HAVING COUNT(*) = 1

Would this work in VFP8?

Thanks in advance.