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PL/SQL trouble
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* PL/SQL trouble
@ 2002-11-26 08:56  Ferruccio Zamuner <nonsolosoft@diff.org>
  0 siblings, 1 reply; 3+ messages in thread

From: Ferruccio Zamuner @ 2002-11-26 08:56 UTC (permalink / raw)
  To: pgsql-sql

Hi,

I really don't understand following PostgreSQL 7.2.3 behaviour:

$ psql mydb
mydb=> CREATE FUNCTION MONDAY(timestamp) RETURNS DATE AS '
 DECLARE 
  var1 date;
 BEGIN
  select into var1 to_date($1::date-(case when extract(DOW from
timestamp $1) = 0 then 6 else (extract(DOW from timestamp $1)-1) end));
  RETURN var1;
 END'
language 'plpgsql';

CREATE
mydb=> select MONDAY('now'::timestamp);
NOTICE:  Error occurred while executing PL/pgSQL function MONDAY
NOTICE:  line 4 at select into variables
ERROR:  parser: parse error at or near "$2"
mydb=> \q

But I've not inserted any $2 there.
I've rewritten the same function in other ways but I've got the same error.

I thank you in advance for any hints.


Bye,                 \fer




^ permalink  raw  reply  [nested|flat] 3+ messages in thread

* Re: PL/SQL trouble
@ 2002-11-26 10:51  Richard Huxton <dev@archonet.com>
  parent: Ferruccio Zamuner <nonsolosoft@diff.org>
  0 siblings, 0 replies; 3+ messages in thread

From: Richard Huxton @ 2002-11-26 10:51 UTC (permalink / raw)
  To: nonsolosoft@diff.org; pgsql-sql

On Tuesday 26 Nov 2002 8:56 am, Ferruccio Zamuner wrote:
> CREATE FUNCTION MONDAY(timestamp) RETURNS DATE AS '
>  DECLARE
>   var1 date;
>  BEGIN
>   select into var1 to_date($1::date-(case when extract(DOW from
> timestamp $1) = 0 then 6 else (extract(DOW from timestamp $1)-1) end));
>   RETURN var1;
>  END'
> language 'plpgsql';

The problem is the to_date(...) - the value is already a date so there isn't a 
to_date that takes a date. You can also remove the timestamp casts:

select into var1 ($1::date -
  (case when extract(DOW from $1) = 0 
    then 6
    else (extract(DOW from $1) - 1 ) end
  )
);

If you put your function in a text file and create it with psql -f you can 
pinpoint errors more easily.

In this case, the $2 was complaining about the second (expected) paramater to 
to_date I think.
-- 
  Richard Huxton



^ permalink  raw  reply  [nested|flat] 3+ messages in thread

* Re: PL/SQL trouble
@ 2002-11-26 11:55  Christoph Haller <ch@rodos.fzk.de>
  0 siblings, 0 replies; 3+ messages in thread

From: Christoph Haller @ 2002-11-26 11:55 UTC (permalink / raw)
  To: nonsolosoft@diff.org; +Cc: pgsql-sql

> I really don't understand following PostgreSQL 7.2.3 behaviour:
>
> $ psql mydb
> mydb=> CREATE FUNCTION MONDAY(timestamp) RETURNS DATE AS '
>  DECLARE
>   var1 date;
>  BEGIN
>   select into var1 to_date($1::date-(case when extract(DOW from
> timestamp $1) = 0 then 6 else (extract(DOW from timestamp $1)-1)
end));
>   RETURN var1;
>  END'
> language 'plpgsql';
>
> CREATE
> mydb=> select MONDAY('now'::timestamp);
> NOTICE:  Error occurred while executing PL/pgSQL function MONDAY
> NOTICE:  line 4 at select into variables
> ERROR:  parser: parse error at or near "$2"
> mydb=> \q
>
> But I've not inserted any $2 there.
> I've rewritten the same function in other ways but I've got the same
error.
>

Something like the following works (as Richard already pointed out):
CREATE OR REPLACE FUNCTION MONDAY(timestamp) RETURNS DATE AS '
 DECLARE
  ts_param    ALIAS FOR $1;
  var1 date;
 BEGIN
  select into var1 to_date(ts_param::date-
  (case when extract(DOW from ts_param) = 0
  then 6 else (extract(DOW from ts_param)-1) end),''DD'');
  RETURN var1;
 END'
language 'plpgsql';

Me personally would prefer another approach:
CREATE OR REPLACE FUNCTION MONDAY(timestamp) RETURNS DATE AS '
 DECLARE
  ts_param    ALIAS FOR $1;
  var1 date;
  var2 double precision;
 BEGIN
  var2 := extract(DOW from ts_param);
  IF var2 = 0 THEN
   var2 := 6;
  ELSE
   var2 := var2 - 1;
  END IF;
  var1 := to_date(ts_param::date - var2,''DD'');
 RETURN var1;
 END'
language 'plpgsql';
because it's easier to read, but that's only a matter of taste I
suppose.

Regards, Christoph




^ permalink  raw  reply  [nested|flat] 3+ messages in thread

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-- links below jump to the message on this page --
2002-11-26 08:56 PL/SQL trouble Ferruccio Zamuner <nonsolosoft@diff.org>
2002-11-26 10:51 ` Richard Huxton <dev@archonet.com>
2002-11-26 11:55 Re: PL/SQL trouble Christoph Haller <ch@rodos.fzk.de>

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