Doing multiple steps at once
Hi,
Basis: I have two tables (a & b).
1st: I create/clear a temporary table c
2nd: doing a "insert into c select something from a"
3rd: doing a "insert into c select something from b"
4th: calculate a result with "select something from c group by column"
5th: go back to 1st after some checks/corrections in a.
Is it possible to do the four steps (1-4) at once (with a function, procedure
or so?)
ciao
Detlef
--
# Dipl. Ing. (FH) Detlef Jockheck
# E-mail: detlef@jockheck.de
# -------------------------------
Detlef Jockheck <detlef@jockheck.de> writes:
1st: I create/clear a temporary table c
2nd: doing a "insert into c select something from a"
3rd: doing a "insert into c select something from b"
4th: calculate a result with "select something from c group by column"
Is it possible to do the four steps (1-4) at once (with a function, procedure
or so?)
Do you need a temp table at all? The given calculation could be done
with something like
SELECT whatever
FROM (SELECT something FROM a
UNION ALL
SELECT something FROM b) ss
GROUP BY column
I can't see a need for a temp table unless your intention is to scan the
UNION result multiple times, in which case building the temp table might
be faster than repeating the UNION.
regards, tom lane