[Dbix-class] Bug with relationships on new objects.

[Matt S Trout]

On Mon, Jan 21, 2008 at 01:04:21PM +0000, Scott Thomson wrote:
> 
> On Jan 7, 2008 8:36 PM, Brett Gardner <brett at clientcomm.com.au> wrote:
> > I'm not saying that the test is incorrect. That is when a foreign key is
> > empty. The case that affects me is when the primary key is empty.
> >
> > To use the examples below, it is like saying that a new Artist owns all
> > the existing CDs even though those CDs have their Artists set, until
> > insert is called.
> >
> > Brett
> >
> >
> > Brett Gardner wrote:
> > > I call new because I then call a method on the object which returns a
> > > list of form controls to edit the object.
> > >
> > > In other cases I also have to set accessors before calling the insert
> > > method.
> > >
> > > Jess Robinson wrote:
> > >>
> > >>
> > >> On Mon, 7 Jan 2008, brett gardner wrote:
> > >>
> > >>> The offending line is on line 793 of ResultSource.pm
> > >>>
> > >>> $ret{$k} = $for->get_column($v) if $for->has_column_loaded($v);
> > >>
> > >> That's because has_column_loaded returns true if the data is in/was
> > >> loaded from the database, you're calling new(), which doesnt insert a
> > >> new row into the database. So it's doing the correct thing.
> > >>
> > >> Call create() instead. That does new() and insert().
> > >>
> > >>> my $undef_artist_cd = $schema->resultset("CD")->new_result({ 'title'
> > >>> => 'badgers', 'year' => 2007 });
> > >>> 207 is($undef_artist_cd->has_column_loaded('artist'), '', 'FK not
> > >>> loaded');
> > >>> 208 is($undef_artist_cd->search_related('artist')->count, 3, 'open
> > >>> search on undef FK');
> > >>
> > >> new_result (or new) don't insert any data in the db, so this is
> > >> perfectly correct.
> > >>
> > >>> in 66relationship.t
> > >>>
> > >>> brett gardner wrote:
> > >>>> I have a schema where there are clients who have subscribers.
> > >>>>
> > >>>> So there is an object "Client" which has a has_many relationship to
> > >>>> "Subscriber".
> > >>>>
> > >>>> If I do the following
> > >>>>
> > >>>> my $client = $app->schema->resultset('Client')->find(...);
> > >>>> my $subscribers = $client->subscribers;
> > >>>>
> > >>>> Then the relationship is correct and only pulls out the subscribers
> > >>>> attached to that client.
> > >>>>
> > >>>> But if I do the following.
> > >>>>
> > >>>> my $client = $app->schema->resultset('Client')->new({});
> > >>>> my $subscribers = $client->subscribers;
> > >>>> Then all the subscribers are pulled out which is not ideal and
> > >>>> potentially a very embarrassing privacy breach. Looking at the SQL
> > >>>> generated by "$client->subscribers" it is not putting in the
> > >>>> limiting where clause "WHERE me.client_id = ..."
> > >>
> > >> As your row is not in the database, how would you expect it to do a
> > >> where?
> > >>
> > >>
> > >> Did you really miss all this, or am I misunderstanding your problem?
> > >>
> > >> Jess
>

<< fixed top-posting and trimmed list footers, learn to use your
   mail clients please people ... >>

> I've also run into a version of this problem. Mine occurs when
> creating an object with an unset FK. It doesn't matter if the object
> is new'd or created - it still doesn't have a key for the FK in
> _column_data.
> 
> I'm considering simply overriding 'new' where appropriate and
> explicitly setting the FK(s) to undef but what concerns me is that the
> behaviour of the created object is different from when the object is
> loaded from the DB and I'm worried that this might bite me elsewhere.

If the column value isn't present at all, maybe related_resultset should
throw an exception on the grounds it can't actually create one yet?

I can't see that breaking any code that isn't already terminally broken -
does one of you guys want to have a go at writing a test case? (because
that's how it'll get fixed :)

-- 
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