From: Mike Rylander <mrylander@gmail.com>
To: Richard Rowell <richard@bowmansystems.com>
Cc: pgsql-sql@postgresql.org
Subject: Re: Recursive SETOF function
Date: Mon, 22 Nov 2004 11:54:30 -0500
Message-ID: <b918cf3d041122085437cde2f1@mail.gmail.com> (raw)
In-Reply-To: <1101136693.18148.66.camel@richard>
References: <1101136693.18148.66.camel@richard>
I'm feeling sausey today, so here is my (untested) attempt to
translate your function. It's inline below, and you'll want to look
here http://www.postgresql.org/docs/7.4/interactive/plpgsql.html for
more information.
On Mon, 22 Nov 2004 09:18:13 -0600, Richard Rowell
<richard@bowmansystems.com> wrote:
> I'm trying to port some TSQL to PLPGSQL. The DB has a table with a
> recursive foreign key that represents a tree hierarchy. I'm trying to
> re-create a TSQL function that pulls out all the ancestors of a given
> node in the hierarchy.
>
> I'm rather new to PLSQL and I have several questions.
>
> 1. In TSQL, I can assign a scalar to the result of query like so:
> SET @var1 = (SELECT foo FROM bar WHERE bar.uid=@var2)
>
> How would I do this in PLSQL?
>
> 2. In TSQL the "result table" can be inserted into manually. IE:
>
> CREATE FUNCTION foo () RETURNS @ttable TABLE( uid INTEGER) AS BEGIN
> INSERT @ttable VALUES (1)
> RETURN
> END
>
> Is there a way to manually insert rows into the result table in PLSQL?
>
> What follows is my TSQL function if that helps give context.
>
> CREATE FUNCTION svp_getparentproviderids (@child_provider INTEGER)
> RETURNS @provider_ids TABLE ( uid INTEGER )
> AS
> BEGIN
> DECLARE @cid AS INTEGER
> IF (SELECT count(*) FROM providers WHERE uid =@child_provider) > 0
> BEGIN
> SET @cid = @child_provider
> WHILE @cid IS NOT NULL
> BEGIN
> INSERT @provider_ids VALUES (@cid)
> SET @cid = (SELECT parent_id FROM providers WHERE uid=@cid)
> END
> END
> RETURN
> END
>
-- This TYPE will get you a named column... easier to use SRFs with a
preexisting type.
CREATE TYPE svp_getparentproviderids_uid_type AS ( uid INTEGER );
CREATE FUNCTION svp_getparentproviderids (INTEGER)
RETURNS SETOF svp_getparentproviderids_uid_type
AS '
DECLARE
child_provider ALIAS FOR $1;
cid INTEGER;
BEGIN
SELECT count(*) FROM providers WHERE uid =@child_provider) > 0
LOOP
cid := child_provider
IF cid IS NULL THEN
EXIT;
END IF;
RETURN NEXT cid;
SELECT INTO cid parent_id FROM providers WHERE uid=@cid;
END LOOP;
RETURN
END;' LANGUAGE 'plpgsql';
Hope that helps!
> --
>
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--
Mike Rylander
mrylander@gmail.com
GPLS -- PINES Development
Database Developer
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To: pgsql-sql@postgresql.org
Cc: mrylander@gmail.com, richard@bowmansystems.com
Subject: Re: Recursive SETOF function
In-Reply-To: <b918cf3d041122085437cde2f1@mail.gmail.com>
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