Re: allowed variable names in functions?

From: "Albe Laurenz" <laurenz(dot)albe(at)wien(dot)gv(dot)at>
To: "A B *EXTERN*" <gentosaker(at)gmail(dot)com>, <pgsql-general(at)postgresql(dot)org>
Subject: Re: allowed variable names in functions?
Date: 2008-06-30 13:48:32
Message-ID: D960CB61B694CF459DCFB4B0128514C20244E034@exadv11.host.magwien.gv.at
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A B wrote:
> Here is the entire function and it fails with the names
> c2,c2div,c3,c3div, but if names are changed, it works!
> (by works I mean I get the "hello" lines printed) There is nothing
> wrong with the select statement either, that works fine if I run it
> stand-alone, or with the names of c2,c2div,c3,c3div changed.
>
> CREATE OR REPLACE FUNCTION foo(pid_ INTEGER) RETURNS void AS $$
> DECLARE
> c2 REAL;
> c2div REAL;
> c3 REAL;
> c3div REAL;
> weights RECORD;
> tmp RECORD;
> retval RECORD;
> t RECORD;
> BEGIN
> RAISE NOTICE 'starting...';
> FOR tmp IN SELECT id,c2,c3 FROM Master WHERE pid=pid_ AND c3 !=0 LOOP
> RAISE NOTICE 'hello %',tmp.id;
> END LOOP;
> RETURN;
> END; $$ LANGUAGE plpgsql;

That is because c2 and c3 in the SELECT statement are replaced with
the variables before the SQL statement is executed.

See the documentation:
http://www.postgresql.org/docs/current/static/plpgsql-implementation.html#PLPGSQL-VAR-SUBST

You should qualify the column names:

SELECT master.id, master.c2, master.c3 FROM master WHERE ... AND master.c3 <> 0

Yours,
Laurenz Albe

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