Re: to_number function questions

On Tue, Sep 17, 2002 at 12:26:57PM -0700, Cindy wrote:
>
> What does to_number do with a string like "123x78" ?  Does
> it try to convert the whole string?  Does it stop at x, giving 123?
> Does it drop x?  Does it return some sort of failure?

test=# select to_number('123x78', '999x99');
 to_number
-----------
     12378

test=# select to_number('123x78', '999');
 to_number
-----------
       123

test=# select to_number('123x78', '999999');
 to_number
-----------
     12378

test=# select to_number('123xxx78', '999yyy99');
 to_number
-----------
     12378

> Also, suppose that you give to_number 123, and the second parameter is
> "999999" ?  Do the extra 9's give any problem (you dn't always know
> whether to_number will get 0-99999, so what do you give it in the
> formatting string?  If it has more 9's in the format string than are
> digits in the number, will it pad it?

test=# select to_number('123', '99999999999999999999999');
 to_number
-----------
       123

> Sorry for all the q's but the page
> http://www.postgresql.org/idocs/index.php?functions-formatting.html
> only lists things in tables and does not discuss the sorts of questions
> or oddball inputs/exceptions I ask about.

 The docs expect that user knows 'psql' and knows method how test wanted
questions before post it to PG lists :-) The patches with better docs are
wanted of course.

    Karel

--
 Karel Zak  <zakkr@zf.jcu.cz>
 http://home.zf.jcu.cz/~zakkr/

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