Re: Function executing twice

From: "Tambet Matiisen" <t(dot)matiisen(at)aprote(dot)ee>
To: "Thiago Conti" <thiago(at)nq(dot)com(dot)br>, "pgsql-sql" <pgsql-sql(at)postgresql(dot)org>
Subject: Re: Function executing twice
Date: 2003-01-30 15:15:03
Message-ID: 000c01c2c872$5d18ab80$0e01a8c0@aprote.com
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I think you should first check your application logic, for example print
something out just before calling the function. Then you can easily see, if
the problem is in PostgreSQL or in your application.

I once had similar problem, when I used function as argument to COALESCE.
COALESCE is translated to CASE before evaluating the arguments. For example
COALESCE(id,nextval('id_seq')) becomes CASE WHEN id IS NOT NULL THEN id WHEN
nextval('id_seq') IS NOT NULL THEN nextval('id_seq') ELSE NULL END. As you
can see, when id is null, the sequence id_seq is incremented twice. Solution
was quite simple, I just used CASE directly: CASE WHEN id IS NOT NULL THEN
id ELSE nextval('id_seq') END.

Tambet

----- Original Message -----
From: Thiago Conti
To: pgsql-sql
Sent: Thursday, January 30, 2003 4:54 PM
Subject: [SQL] Function executing twice

Hello,

I'm executing a function with this command:
select function_name(aaa,bbb,ccc);

When I do it on PSQL or PGAdmin it works perfectly.
However, on my application the function is executed twice.

Has anybody faced a problem like this?

I'm using PostgreSQL 7.2.3 and ODBC conection.

Thanks

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