Stored procedure returning row or resultset

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От Heiko Stoermer
Тема Stored procedure returning row or resultset
Дата
Msg-id 200210141622.54638.heiko.stoermer@login-solutions.de
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Ответы Re: Stored procedure returning row or resultset  (Richard Huxton <dev@archonet.com>)
Список pgsql-sql
Hello,

I'm trying to achieve the following with pl/pgsql in postgres 7.2:

I need a stored procedure proc() that calculates values for some fields
a = f1()
b = a + f2()
c = b + f3()
and returns the tuple (a,b,c) as a rowtype,

so that "select proc()" produces a "normal" resultset that can be used in an 
application.


I know of course that I could write out
SELECT
(f1()) AS a
(f1() + f()) AS b
(f1() + f2() + f3()) AS c ...
in plain SQL and create a view on that, but the problem is that f1(), f2(), 
f3() are complex and expensive computations that I want to run only once. In 
the example I would call f1() three times, which is inacceptable.

Is there a way to accomplish this? I have tried around quite a bit, but I 
cannot find out the correct syntax .

Thank you,
Heiko Stoermer

-- 
Heiko Stoermer
Diplom-Informatiker (FH)             Login & Solutions AG
Tel.: +49-821-2488-0                 http://www.login-solutions.de



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