-- Oracle: Example for Insert or update in t1 from t2 values 
MERGE INTO table1 t1
USING table2 t2
ON (t1.CODE = t2.ID)
WHEN MATCHED THEN
    UPDATE SET t1.COL1 = t2.VALUE1
WHEN NOT MATCHED THEN
    INSERT (CODE, COL1)  VALUES (t2.ID, t2.VALUE1);