Hi,
I'm trying to do a request but I can't figure out how to do it.
Basically I have 1 table with 3 fields (field1,field2,field3).
Values in those 3 fields can be the same, but I want to select all of
these values only once (i.e distinct values)

Example

Field1 Field2 Field3
A A A
B E B
C F F
D G H

The select should return: A,B,C,D,E,F,G,H
I've tried with union and a select not in but I ended up with something
big and I got confused.
Can someone help ?
Thx