You can create a view to hold the output of the two queries as
CREATE VIEW MYUNIONDATE AS
(SELECT Name, MaxOfDateQC
FROM vw_vendor_current_mech
UNION ALL
SELECT Name, MaxOfDateQC
FROM vw_vendor_current_elec)
GO
UPDATE TblVendors SET TblVendors.Vendor = 1
WHERE TblVendors.Name IN (SELECT [Name] FROM MYUNIONDATE)
Thanks
Prasad Bhogadi
www.inforaise.com