[SQL] help on a function with exception

[M. D.]

Hi,

I want to do a check on a column if other columns meet certain 
conditions. The program I'm working with allows to create additional 
columns on every 'object' - called extra data, but I have no control 
over the program.  I want to enforce the values on this one extra data 
to be of type date.


My idea was to do a Trigger function and cast to a date and if there's 
an exception, raise an error.  Below is what I've tried, but it just 
keeps on Raising Exception.


Could someone please help me? The date I enter is: 2012-10-10 which 
works fine if I do a:

select '2012-10-10'::date

Thanks

--Postgres 9.0

CREATE OR REPLACE FUNCTION fnc_check_PO_extra_date()
  RETURNS trigger AS
$BODY$
DECLARE
tmp_date date;
BEGIN
  IF (TG_OP = 'INSERT' OR TG_OP = 'UPDATE') THEN
IF (NEW.data_value IS NOT NULL or new.data_value = '') and 
NEW.extra_id =

(select extra_id from extra_data where data_type = 9
and (data_name = 'ETA' or data_name = 'Adjusted ETA'))
THEN
tmp_date := new.data_value::date;
END IF;
  END IF;
  EXCEPTION
WHEN others THEN
RAISE EXCEPTION 'Invalid date on Extra Data!';
return NEW;
END;
$BODY$
LANGUAGE plpgsql VOLATILE

CREATE TRIGGER trg_check_PO_extra_date
  BEFORE INSERT OR UPDATE
  ON extra_values
  FOR EACH ROW
  EXECUTE PROCEDURE fnc_check_PO_extra_date();

--
Sent via pgsql-sql mailing list (pgsql-sql@postgresql.org)
To make changes to your subscription:
http://www.postgresql.org/mailpref/pgsql-sql

Re: [SQL] help on a function with exception

[David Johnston]

On Mar 13, 2012, at 14:29, "M. D."  wrote:

> Hi,
> 
> I want to do a check on a column if other columns meet certain conditions. 
> The program I'm working with allows to create additional columns on every 
> 'object' - called extra data, but I have no control over the program.  I want 
> to enforce the values on this one extra data to be of type date.
> 
> My idea was to do a Trigger function and cast to a date and if there's an 
> exception, raise an error.  Below is what I've tried, but it just keeps on 
> Raising Exception.
> 
> Could someone please help me? The date I enter is: 2012-10-10 which works 
> fine if I do a:
> select '2012-10-10'::date
> 
> Thanks
> 
> --Postgres 9.0
> 
> CREATE OR REPLACE FUNCTION fnc_check_PO_extra_date()
>  RETURNS trigger AS
> $BODY$
> DECLARE
>tmp_date date;
> BEGIN
>  IF (TG_OP = 'INSERT' OR TG_OP = 'UPDATE') THEN
>IF (NEW.data_value IS NOT NULL or new.data_value = '') and NEW.extra_id =
>(select extra_id from extra_data where data_type = 9
>and (data_name = 'ETA' or data_name = 'Adjusted ETA'))
>THEN
>tmp_date := new.data_value::date;
>END IF;
>  END IF;
>  EXCEPTION
>WHEN others THEN
>RAISE EXCEPTION 'Invalid date on Extra Data!';
> return NEW;
> END;
> $BODY$
> LANGUAGE plpgsql VOLATILE
> 
> CREATE TRIGGER trg_check_PO_extra_date
>  BEFORE INSERT OR UPDATE
>  ON extra_values
>  FOR EACH ROW
>  EXECUTE PROCEDURE fnc_check_PO_extra_date();
> 
> 

You are suppressing the original exception so figuring out what is wrong is 
very difficult.

Your IF allows new.data_value to be the empty string which, iirc,  cannot be 
cast to date

David J.


-- 
Sent via pgsql-sql mailing list (pgsql-sql@postgresql.org)
To make changes to your subscription:
http://www.postgresql.org/mailpref/pgsql-sql