Re: [GENERAL] plpgsql question: select into multiple variables ?

[Day, David]

Hi Yari,

Thanks for the response.
You did make the “simplified concept” function more rational.

However,
This was kind of a non-sense function to demonstrate the problem I was having 
with the “select fields” and the “into variables”.
As pointed out by Adrian Klaver and  Tom Lane,  the real problem was in casts 
that I was using were confusing the parser and were un-necessary.

Appreciate your thought and effort.


Regards


Dave



From: Yasin Sari [mailto:yasinsar...@googlemail.com]
Sent: Tuesday, June 30, 2015 3:26 AM
To: Day, David
Subject: Re: [GENERAL] plpgsql question: select into multiple variables ?

Hi David,

this works for me.

CREATE OR REPLACE FUNCTION sys.time_test (
  out first_weekend date,
  out last_weekend date
)
RETURNS SETOF record AS
$body$
BEGIN


  SELECT 
COALESCE(MIN(CAL_DATE),'01-jun-2014'),COALESCE(MAX(CAL_DATE),'01-jun-2014')
  into first_weekend,last_weekend
  FROM sys.calendar
WHERE month_of_year = (extract(MONTH FROM current_date))::int AND
              year_of_date = (extract(YEAR FROM current_date))::int AND
             day_of_week IN ( 'Sat','Sun');
return next;

END
$body$
LANGUAGE 'plpgsql'
VOLATILE
CALLED ON NULL INPUT
SECURITY INVOKER
COST 100 ROWS 1000;

On Mon, Jun 29, 2015 at 10:07 PM, Day, David 
<d...@redcom.com<mailto:d...@redcom.com>> wrote:
Hi,



Postgres version 9.3.9


What is wrong with my usage of the plpgsql  "select into" concept
I have a function to look into a calendar table to find the first and
Last weekend date of a month.

In this simplified concept function I end up with a NULL for first or last 
weekend variable.


create or replace function sys.time_test ()
returns date as
$$
DECLARE
   first_weekend date;
   last_weekend date;
BEGIN

  SELECT MIN(CAL_DATE),MAX(CAL_DATE) INTO first_weekend::date, 
last_weekend::date FROM sys.calendar
          WHERE month_of_year = (extract(MONTH FROM current_date))::int AND
              year_of_date = (extract(YEAR FROM current_date))::int AND
             day_of_week IN ( 'Sat','Sun');

 RETURN( COALESCE(last_weekend,'01-jun-2014'));

END
$$
LANGUAGE plpgsql volatile;


If I execute the same select logic from a psql shell I get the correct result.


(1 row)

ace_db=# ace_db=#  SELECT MIN(CAL_DATE),MAX(CAL_DATE) FROM sys.calendar cal     
                                                                                
                                        WHERE cal.month_of_year = 
(extract(MONTH FROM current_date))::int AND                                     
                                                                 
cal.year_of_date = (extract(YEAR FROM current_date))::int AND                   
                                                                                
     cal.day_of_week IN ( 'Sat','Sun');
    min     |    max
------------+------------
 2015-06-06 | 2015-06-28
(1 row)


If I simplify to a single variable it works. i.e


create or replace function sys.time_test ()
returns date as
$$
DECLARE
   first_weekend date;
   last_weekend date;
BEGIN

  SELECT MIN(CAL_DATE) INTO first_weekend::date FROM sys.calendar
          WHERE month_of_year = (extract(MONTH FROM current_date))::int AND
              year_of_date = (extract(YEAR FROM current_date))::int AND
             day_of_week IN ( 'Sat','Sun');

 RETURN( COALESCE(first_weekend,'01-jun-2014'));

END
$$
LANGUAGE plpgsql volatile;



I suppose I can adjust to write my actual function to have 2 selects; one for 
each variable.
However, I thought according to the documentation the targets could/must match 
the result columns for select into ?


Thoughts


Thanks


Dave Day




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