Обсуждение: PL/PGSQL

Hello everybody,

I'm Jordi from Spain, I'm new on this mailing list. I hope I could help anybody in the future but now I new some help because I read a lot of documentation but I can't find an answer.

I have two  questions:

--------------------------------------------------------------------------------------------------
1.- Exception throwed by cast('yyyymmdd' as timestamp)

I do a cast conversion from a string to a timestamp. When I put a bad date on the string, the cast throw an error on my PL/PGSQL but I can't capture (I'm new). Which type of exception launch the cast function?

I put a exception space on my function but I don't know which exception I have ti capture:

EXCEPTION
WHEN exception_name  THEN
    statements;

Which exception _name I have to write on my code?
--------------------------------------------------------------------------------------------------
2.- Number of days on February

I'm parsing a string with a date with format 'yyyymmdd' for testing if it's a valid date.

I need to know if the day is correct for the month on the string, but February is different for every year. How can I know if February have 28 or 29 days depending on the year?

Thanks everybody and hello from a new user ;-)

Hi,

Welcome aboard :)

Jordi Martínez <jmartinez@uic.es> writes:
> 1.- Exception throwed by cast('yyyymmdd' as timestamp)
>
> I do a cast conversion from a string to a timestamp. When I put a bad
> date on the string, the cast throw an error on my PL/PGSQL but I can't
> capture (I'm new).  Which type of exception launch the cast function?

The exhaustive list of error codes is there:

  http://www.postgresql.org/docs/8.3/static/errcodes-appendix.html

It should probably be in Class 22 — Data Exception, and I'd bet one of
those, depending on the faulty input:

  22008    DATETIME FIELD OVERFLOW    datetime_field_overflow
  22007    INVALID DATETIME FORMAT    invalid_datetime_format

> 2.- Number of days on February
>
> I'm parsing a string with a date with format 'yyyymmdd' for testing if it's a valid date.
>
> I need to know if the day is correct for the month on the string, but
> February is different for every year. How can I know if February have
> 28 or 29 days depending on the year?

The usual trick is to ask for the day number of 03/01 preceeding day:

dim=# select x::date, extract(day from x::date - interval '1 day')
        from (values('20090301'), ('20080301'),
                    ('20040301'), ('20000301')) as t(x);
     x      | date_part
------------+-----------
 03-01-2009 |        28
 03-01-2008 |        29
 03-01-2004 |        29
 03-01-2000 |        29
(4 lignes)

Regards,
--
dim

mg>hopefully quick response

Hello everybody,

I'm Jordi from Spain, I'm new on this mailing list. I hope I could help anybody in the future but now I new some help because I read a lot of documentation but I can't find an answer.

I have two  questions:

--------------------------------------------------------------------------------------------------
1.- Exception throwed by cast('yyyymmdd' as timestamp)

I do a cast conversion from a string to a timestamp. When I put a bad date on the string, the cast throw an error on my PL/PGSQL but I can't capture (I'm new). Which type of exception launch the cast function?

I put a exception space on my function but I don't know which exception I have ti capture:

EXCEPTION
WHEN exception_name  THEN
MG>when VALUE_ERROR THEN
MG>DBMS_OUTPUT.PUT_LINE('Cannot convert STRING to DATE');

    statements;

Which exception _name I have to write on my code?
--------------------------------------------------------------------------------------------------
2.- Number of days on February

I'm parsing a string with a date with format 'yyyymmdd' for testing if it's a valid date.

I need to know if the day is correct for the month on the string, but February is different for every year. How can I know if February have 28 or 29 days depending on the year?
MG>select TO_CHAR(DATE_COLUMN,'DD') FROM TABLE;

Thanks everybody and hello from a new user ;-)

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