I am currently trying to obtain data from two tables that have the same columns. The values for primary key "ID" of both tables may exist in one or both tables. Even with same primary keys, the values in different columns may not be the same for both tables. My question is given I have an ID testID, how do I query where in I first check table1 if it exists. If it exists in table1 I use the details found in table1, otherwise check table2 and use details in table2 if it exists in table2.