MERGE INTO TARGET_TABLE USING DUAL
         ON cola = 'a' AND colb = 'b'
        WHEN NOT MATCHED THEN
             INSERT VALUES ('a', 'b', 'cc', 1, 'zz')
        WHEN MATCHED THEN UPDATE SET colc = 'cc', col1 = TARGET_TABLE.col1 + 1  --Aggregation
        colz = CASEWHEN(TARGET_TABLE.colz IS NULL, 'zz', TARGET_TABLE.colz ); --check if it is null