From: Christopher Kings-Lynne <chriskl@familyhealth.com.au>
To: Fritz Lehmann-Grube <lehmannf@math.TU-Berlin.DE>
Cc: pgsql-sql@postgresql.org
Subject: Re: recursive function returning "setof"
Date: Mon, 19 Aug 2002 23:52:56 +0800
Message-ID: <00a401c24798$7cc43630$0200a8c0@SOL> (raw)
References: <3D60F041.10003@math.tu-berlin.de>
<006b01c24790$072149c0$0200a8c0@SOL>
<3D610D1A.6020009@math.tu-berlin.de>
http://www3.us.postgresql.org/users-lounge/docs/7.2/postgres/plpgsql-control
-structures.html
Chris
----- Original Message -----
From: "Fritz Lehmann-Grube" <lehmannf@math.TU-Berlin.DE>
To: "Christopher Kings-Lynne" <chriskl@familyhealth.com.au>
Cc: <pgsql-sql@postgresql.org>
Sent: Monday, August 19, 2002 11:22 PM
Subject: Re: [SQL] recursive function returning "setof"
>
> Thanx Chris,
>
> but I can't find it.
> My Programmer's Guide (.../pgsql/doc/html/xfunc-sql.html) says
>
> "12.2. Query Language (SQL) Functions
> SQL functions execute an arbitrary list of SQL statements,"
>
> Nothing about control structures in SQL functions additional to the normal
> command-line syntax. Where can I find it ?
>
> and (.../pgsql/doc/html/plpgsql.html#PLPGSQL-ADVANTAGES)
>
> "23.1.1.1. Better Performance
> SQL is the language PostgreSQL (and most other Relational Databases)
use as
> query language. It's portable and easy to learn. But every SQL
statement
> must be executed individually by the database server.
>
> That means that your client application must send each query to the
database
> server, wait for it to process it, receive the results, do some
computation,
> then send other queries to the server."
>
> Isn't it just the thing in plpgsql to add control structures to SQL ?
>
> Fritz
>
> Christopher Kings-Lynne wrote:
> >>The problem is:
> >>A SQL-Function cannot be recursive because it cannot call itself, and it
> >
> > can
> >
> >>perform no loops.
> >>A PLPGSQL-Function cannot return sets.
> >
> >
> > It can perform loops. Check the manual- you can do FOR and WHILE loops.
> > 7.3 will be able to return sets from PLPGSQL funcs it seems.
> >
> > Chris
> >
> >
> >
> > ---------------------------(end of broadcast)---------------------------
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> >
>
>
>
>
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To: pgsql-sql@postgresql.org
Cc: chriskl@familyhealth.com.au, lehmannf@math.TU-Berlin.DE
Subject: Re: recursive function returning "setof"
In-Reply-To: <00a401c24798$7cc43630$0200a8c0@SOL>
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