Re: Trying to avoid a simple temporary variable declaration in a pl/pgsql function

"David G. Johnston" <david.g.johnston@gmail.com> writes:

> On Sat, Jun 20, 2015 at 10:56 AM, Tom Lane <tgl@sss.pgh.pa.us> wrote:
>
>     "David G. Johnston" <david.g.johnston@gmail.com> writes:
>     > I know this could be written quite easily in sql but was wondering if it is
>     > possible in pl/pgsql.
>
>     > CREATE FUNCTION test_func()
>     > RETURNS text
>     > LANGUAGE 'plpgsql'
>     > AS $$
>     > BEGIN
>     > SELECT 'text_to_return' INTO <what_goes_here?>; --with or without a cast
>     > RETURN <what_goes_here?>;
>     > END;
>     > $$;
>
>     > The goal is to return the value of text_to_return without declaring an
>     > explicit variable to name in the INTO clause.
>
>     INTO requires a declared variable as target.
>
>     However, I'm wondering why you don't just use "RETURN expression"
>     if this is all that will be in the function.
>
> ​The use of SELECT is required and will likely have a CTE
> and a set of SQL CASE expressions as part of it.  ​ It
> isn't a problem to declare it myself but I thought I had read about
> there being an implicit variable name that could be used instead. 
> I guess I mis-remembered...

Try this...


sj$ psql -eqf q
begin;
create table foo as
select 'here goes some text'::text as tf;
create  function foo ()
returns text
as $$
begin
    return  case when true then tf end from foo limit 1;
end
$$ language plpgsql;

select foo();
         foo
---------------------
 here goes some text
(1 row)

abort;
sj$

HTH
>


> ​Thanks for the quick response.
>
> David J.
>

--
Jerry Sievers
Postgres DBA/Development Consulting
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