Query question ( I am having a senior moment)

Question

I have 2 talbes
Table One
Key Value
A 1
A 2
A 3
A 4
B 1
B 2
B 3
Table Two
Key Value
A A
A B
B A
B B
B C
B D
B E
I want to return :
Key Value1 Value2
A 1 A
A 2 B
A 3
A 4
B 1 A
B 2 B
B 3 C
B D
B E
How can I write this query ??
Thanks..

Answer 1

In deference to your seniority :P, I won't point out that you neglected to tell us how table one value joins to table two value, so you'll have to adapt thi sto meet your own needs.
SELECT * FROM
   (SELECT t1.keyval as key, t1.val as value1, t2.val as value2
    FROM   t_one t1, t_two t2
    WHERE  t1.keyval = t2.keyval(+)
    AND    decode(t2.val(+), 'A', 1, 'B', 2, 'C', 3, null) = t1.val
    UNION
    SELECT t2.keyval as key, t1.val as value1, t2.val as value2
    FROM   t_one t1, t_two t2
    WHERE  t1.keyval(+) = t2.keyval
    AND    decode(t2.val, 'A', 1, 'B', 2, 'C', 3, null) = t1.val(+))
If you're using 9i you might want to investigate the ANSI FULL OUTER JOIN syntax, which is much neater.
Cheers, APC