Table 1 Field1 Field2 1 John 2 Joe 3 Jim Table2 Field1 Field2 1 Baseball 2 Tennis 3 Croquet Result Set 1 select t1.field1, t1.field2, 0 as field3, space(8) as field4 from table1 t1 union select 0 as field1, space(8) as field2, t2.field1 as field3, t2.field2 as field4 from table1 t2 Field1 Field2 Field3 Field4 1 John 0 2 Joe 0 3 Jim 0 0 1 Baseball 0 2 Tennis 0 3 Croquet Result Set 2 select t1.field1, t1.field2 from table1 t1 union select t2.field1, t2.field2 from table1 t2 Field1 Field2 1 John 2 Joe 3 Jim 1 Baseball 2 Tennis 3 CroquetChanges in result set 1 can be sent to the backend. Field1 and Field3 would need to be configured as key values. Changes in result set 2 can not. There is no way of telliong which table each row comes from.