Re: What is the best way to merge two disjoint tables?

On 9/7/07, Chansup Byun <Chansup(dot)Byun(at)sun(dot)com> wrote:
> Can someone show me an example SQL statement?

I suppose you could add a constant, non-overlapping number to add to
the duplicate IDs, say 1000, and then this:

SELECT COALESCE(T1.U_USER, T2.U_USER) AS U_USER
, COALESCE(CASE
WHEN EXISTS(SELECT 1
FROM TABLEB
WHERE U_ID = T1.U_ID
AND U_USER <> T1.U_USER)
THEN T1.U_ID + 1000
ELSE T1.U_ID
END
, T2.U_ID
) AS U_ID
FROM TABLEA T1 FULL JOIN TABLEB T2 ON T1.U_USER = T2.U_USER

will generate a new list of U_USERs and U_IDs.

Good luck.