Question

I have a mysql table that has two fields that store the same type of information. I want to retrieve all unique values in those two fields.

If it were just one field I could do:

SELECT distinct FIELD1 FROM table

How can I get all unique values from FIELD1 and FIELD2

Clarification:
I don’t mean unique pairs.

Say field1 contains 1,13,5,25,13,8
and field2 contains 6,10,1,30,13

I want a query that returns 1,13,5,25,8,6,10,30

Answer 1

Try this

select distinct * FROM (
  select distinct field1 as n from table
    union 
  select distinct field2 as n from table) as t;