Question

I have two tables

Table 1:

    ref       status

    abc     1
    abc     1
    abc     2
    abc     3
    abc     5(not in Table2)
    abc     5(not in Table2)

Table 2:

    ref          status

    abc     1
    abc     1
    abc     2
    abc     3
    abc             4(not in Table1)
    abc     4(not in Table1)

I want to join these two tables and perform a grouping so that the final result looks like this:

Resultant Table:
ref status

    abc     1
    abc     2
    abc     3
    abc     4
    abc     5

I have tried this

    SELECT DISTINCT Table1.ref, Table1.status, Table2.ref, Table2.status
    FROM Table1, Table2
    GROUP BY Table1.ref, Table1.status, Table2.ref, Table2.status;

Answer 1

SELECT DISTINCT ref, status
FROM
(
    SELECT ref, status
    FROM Table1
    UNION ALL
    SELECT ref, status
    FROM Table2
) x

SQL Fiddle example