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

Rodrigo De León wrote:
> On 9/7/07, Chansup Byun <Chansup.Byun@sun.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.
>
This is cool!
What I wanted is shown below.

One more question: Is there a way to make the  T2.U_ID + 1000  number to be incremental from a given number instead of
adding1000? 


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
                  ELSE T1.U_ID
                END
              , T2.U_ID + 1000
               ) AS U_ID
  FROM TABLEA T1 FULL JOIN TABLEB T2 ON T1.U_USER = T2.U_USER



thanks,

- Chansup