Обсуждение: create function using language SQL

Hi all,

As I was reading up on create function etc. while learning plpgsql, I seam to 
remember it stated that as well as plpgsql, that other languages are/will be 
available including using SQL as the language.  However, I cannot find the 
syntax to create a function in SQL.  Specifically, how you return the result.

As an example, how would I create a SQL function to match the plpgsql 
function below?


CREATE FUNCTION getteamno(int4) RETURNS varchar  AS '
DECLARE    unitno varchar;
BEGIN   select into unitno       tregion || ''/'' ||to_char(tnumber,''FM000'')       from teams       where tid = $1;
ifnot found then     raise exception ''Team % not found'',$1;     return '''';   end if;   return unitno;
 
END;
' LANGUAGE 'plpgsql';

-- 
Gary Stainburn
This email does not contain private or confidential material as it
may be snooped on by interested government parties for unknown
and undisclosed purposes - Regulation of Investigatory Powers Act, 2000     

The "create function" syntax is the same.  The language syntax is straight
SQL:

CREATE FUNCTION getteamno(int4) RETURNS varchar AS '
SELECT tregion || ''/'' || to_char(tnumber, ''FM000'')
FROM teams
WHERE tid = $1
' LANGUAGE 'sql';

You don't get to build in error checking, but there has to be a reason to
use plpgsql :-)
SQL is non-procedural, after all.
Check the docs: Reference Manual/SQL Commands/Create Function
----- Original Message -----
From: "Gary Stainburn" <gary.stainburn@ringways.co.uk>
To: <pgsql-sql@postgresql.org>
Sent: Tuesday, August 14, 2001 7:40 AM
Subject: create function using language SQL


> Hi all,
>
> As I was reading up on create function etc. while learning plpgsql, I seam
to
> remember it stated that as well as plpgsql, that other languages are/will
be
> available including using SQL as the language.  However, I cannot find the
> syntax to create a function in SQL.  Specifically, how you return the
result.
>
> As an example, how would I create a SQL function to match the plpgsql
> function below?
>
>
> CREATE FUNCTION getteamno(int4) RETURNS varchar  AS '
> DECLARE
>      unitno varchar;
> BEGIN
>     select into unitno
>         tregion || ''/'' ||
> to_char(tnumber,''FM000'')
>         from teams
>         where tid = $1;
>     if not found then
>       raise exception ''Team % not found'',$1;
>       return '''';
>     end if;
>     return unitno;
> END;
> ' LANGUAGE 'plpgsql';
>
> --
> Gary Stainburn
>
> This email does not contain private or confidential material as it
> may be snooped on by interested government parties for unknown
> and undisclosed purposes - Regulation of Investigatory Powers Act, 2000
>
> ---------------------------(end of broadcast)---------------------------
> TIP 6: Have you searched our list archives?
>
> http://www.postgresql.org/search.mpl
>
>

Gary Stainburn <gary.stainburn@ringways.co.uk> writes:
> ... However, I cannot find the 
> syntax to create a function in SQL.  Specifically, how you return the result.

See
http://www.ca.postgresql.org/users-lounge/docs/7.1/postgres/xfunc.html#XFUNC-SQL
        regards, tom lane