Re: Substitutes for subqueries (subselects)?

"Kurta" <submit_at_galleus.com> schrieb im Newsbeitrag news:efcb1994.0403020208.33ed38f_at_posting.google.com...
> I have a SELECT query that uses subselects:
>
> SELECT
> SAV_ID
> FROM
> T_SVGS
> WHERE
> (SAV_MEMB = 66470
> OR
> SAV_CM_BASE IN (SELECT CMBS_ID FROM T_CM_BASEBASE AA WHERE CMBS_MEMB
> = 66470)
> OR
> SAV_UM_BASE IN (SELECT UMBS_ID FROM T_UM_BASE BB WHERE UMBS_MEMB =
> 66470))
>
> I'd have to return additional columns from the tables of the
> subqueries. I can achieve a desired result with joins and unions like
> this:
>
> SELECT
> SAV_ID, SAV_MEMB, NULL CLASSTYPE
> FROM
> T_SVGS
> WHERE
> SAV_MEMB = 66470
>
> UNION
>
> SELECT
> SAV_ID, SAV_CM_BASE, CMBS.CLASSTYPE
> FROM
> T_SVGS, T_CM_BASEBASE CMBS
> WHERE CMBS_ID = SAV_CM_BASE AND CMBS_MEMB = 66470
>
> UNION
>
> SELECT
> SAV_ID, SAV_UM_BASE, UMBS.CLASSTYPE
> FROM
> T_SVGS, T_UM_BASE UMBS
> WHERE UMBS_ID = SAV_UM_BASE AND UMBS_MEMB = 66470
>
> Is there a less harmful way to get the same results without having to
> rewrite all the queries?
>
> Thanks for your help.
>
> Kurta

Kurta, I fear the answer is no, there is no nice tool for this.

That would be a really nice tool, that could rewrite all concerning selects correctly
with *zero* knowledge of the business rules behind them (and in the real world many lack to use fk constraints and so on ...)

On the other hand, it could
actually make some SQL "artists" loosing their jobs ... maybe it will come with programming languages of the 10th generation in 2020, who knows ...

So far, good SQL remains an art. Few are real artists, many arenīt.

Not much help, sorry, but this is how I see it. Greetings, Jan Received on Wed Mar 03 2004 - 09:54:55 CST