Re: mysql_query returning empty result after DELETE

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OK.

If I change the test to "if(mysql_num_rows($thisRow) < 1)" it does what I
want.

I guess if I want to understand why False was returned originally (just
after I created the database) I need to start over.

Do I have 4 possible conditions here: 1) the mysql_query() function fails
and I get a PHP error, 2) the query fails at the server and I get False, or
3) the query doesn't fail at the server and I get "a result" that a) is
empty, or b) contains 1 or more rows?  Yes.

Problem solved (my code was naive), understanding increased (my code won't
be naive in the future as regards mysql functions in PHP).

Thank you very much..

"Chris" <dmagick@xxxxxxxxx> wrote in message
news:4AAD74E5.3090505@xxxxxxxxxxxx
> Stan wrote:
> > I did a "DELETE FROM picture" where "picture" is a table in my database.
>
> Because this deletes all your records - so doing a select afterwards
> will find nothing.
>
> > Afterward, this piece of code does not generate an error
> > ----------------------------------------------
> > try
> >       {
> >       $query = "SELECT * FROM picture p " .
> >                           "WHERE p.pictureFile='" . $pictureFile . "'";
> >       $thisRow =
> >               mysql_query($query, $pictures_connection);
> >       }
> >       catch(Exception $e)
> >              {
> >              echo 'caught exception: ',  $e->getMessage()."\n";
> >              $result = False;
> >              }
>
> an empty result set is fine - it means no records found. It will not
> generate an exception.
>
> I'm not sure when mysql will generate an exception either, mysql_query
> returns FALSE if the query fails (see http://www.php.net/mysql_query).
> You then have to use mysql_error to get the reason why it failed.
>
> -- 
> Postgresql & php tutorials
> http://www.designmagick.com/
>



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