DB Query Execution Error

Error # 1064
You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near ')'' OR IS NULL) AND PROD.Display='Yes') AND CATEGORY_VENDOR_PROD.ProdId=PROD.Id' at line 1



DatabaseTools->FindData
query=SELECT DISTINCT VENDOR.Id, VENDOR.Name FROM TravelCountry.CATEGORY_VENDOR_PROD,TravelCountry.PROD,TravelCountry.VENDOR WHERE ((()'' OR IS NULL) AND PROD.Display='Yes') AND CATEGORY_VENDOR_PROD.ProdId=PROD.Id AND PROD.VendorId=VENDOR.Id GROUP BY PROD.Id ORDER BY VENDOR.Name ASC
Type=array->hash
Key=