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In-Reply-To: <hpk5kd$98o$1@dough.gmane.org>
References: <hpk5kd$98o$1@dough.gmane.org>
Date: Thu, 8 Apr 2010 11:01:20 +0200
Message-ID: <j2o162867791004080201i773a63cfg6b3f9d233cf40417@mail.gmail.com>
Subject: Re: Problem with function returning a result set
From: Pavel Stehule <pavel.stehule@gmail.com>
To: Thomas Kellerer <spam_eater@gmx.net>
Cc: pgsql-sql@postgresql.org
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2010/4/8 Thomas Kellerer <spam_eater@gmx.net>:
> Hi,
>
> I'm playing around with functions returning result sets, and I have a
> problem with the following function:
>
> -- Create sample data
> CREATE TABLE employee (id integer, first_name varchar(50), last_name
> varchar(50));
> INSERT INTO employee values (1, 'Arthur', 'Dent');
> INSERT INTO employee values (2, 'Zaphod', 'Beeblebrox');
> INSERT INTO employee values (3, 'Ford', 'Prefect');
> COMMIT;
>
> -- Create the function
> CREATE OR REPLACE FUNCTION get_employees(name_pattern varchar)
> RETURNS TABLE(id integer, full_name text)
> AS
> $$
> BEGIN
>
> =C2=A0RETURN QUERY
> =C2=A0 =C2=A0SELECT id, first_name||' '||last_name
> =C2=A0 =C2=A0FROM employee
> =C2=A0 =C2=A0WHERE last_name LIKE name_pattern ||'%';
> END
> $$
> LANGUAGE plpgsql;
>
> COMMIT;
>
> Now when I run:
>
> SELECT *
> FROM get_employees('D');
>
> I get one row returned which is correct, but the ID column is null (but
> should be 1). It does not depend which row(s) I select through the
> procedure. I also tried to change the datatype of the returned id to int8
> and an explicit cast in the SELECT statement, but to no avail.
>
> When I define the function using SQL as a language (with the approriate
> changes), the ID column is returned correctly.
>
> I'm using Postgres 8.4.3 on Windows XP
> postgres=3D> select version();
> =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=
=A0 =C2=A0 =C2=A0 version
> -------------------------------------------------------------
> =C2=A0PostgreSQL 8.4.3, compiled by Visual C++ build 1400, 32-bit
> (1 row)
>
> What am I missing?

there are collision between SQL and PLpgSQL identifiers.

 RETURNS TABLE(id integer, full_name text) AS
 $$
 BEGIN
  RETURN QUERY
    SELECT e.id, e.first_name||' '||e.last_name
    FROM employee e
    WHERE e.last_name LIKE e.name_pattern ||'%';
 END
 $$
 LANGUAGE plpgsql;

use aliases.

Regards
Pavel Stehule

>
> Regards
> Thomas
>
>
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