[Dbix-class] Re: Testing for a join

[Hernan Lopes]

i think this ?
http://search.cpan.org/~frew/DBIx-Class-0.08124/lib/DBIx/Class/ResultSource=
.pm#relationships

On Fri, Dec 17, 2010 at 5:23 PM, Bill Moseley <moseley at hank.org> wrote:

> To be a bit more succinct:
>
> Is there a method to see if a given $rs will join to (or query from) table
> "foo" and if so what alias is used?
>
> I guess I could use $rs->as_query and a regular expression but wondered if
> there might be a way that doesn't need to build the entire query.
>
>
>
> On Thu, Dec 16, 2010 at 4:59 PM, Bill Moseley <moseley at hank.org> wrote:
>
>>
>> Music Database:  label -> cd -> track -> movement -> note
>>
>> So, there's a hierarchy of objects.
>>
>> Say, label has a "deleted" flag that always needs to be checked.  So, one
>> option is to join and then add the check constraint in the base class:
>>
>> $rs =3D $schema->resultset( 'Track' )->join_label->check_deleted;
>> $rs =3D $schema->resultset( 'Cd' )->join_label->check_deleted;
>> $rs =3D $schema->resultset( 'Note' )->join_label->check_deleted;
>>
>>
>> Where join_label() is a method in the specific resultset class -- e.g.
>> ResultSet::CD has method join_label { return shift->search( undef, { joi=
n =3D>
>> 'label' } ) }, and likewise, ResultSet::Note has a join_label method that
>> joins from note all the way to label.
>>
>> And then in the base ResultSet class check_deleted adds this to the
>> resultset: sub check_deleted { return shift->search( { 'label.deleted' =
=3D> 0
>> } ); }
>>
>> That works because every object is joined to the label object.
>>
>>
>> Now, assume there's also a "deleted" flag on the track object.  If
>> fetching a CD or Label then don't want to add a track.deleted =3D> 0
>> condition, but if fetching track, movement, or a note I do want to add t=
hat
>> condition.
>>
>> Is it possible to "know" in the base "check_deleted' method that the $rs
>> is fetching either a track (or is joined to track) and then conditionally
>> add the track.deleted check?
>>
>>
>> --
>> Bill Moseley
>> moseley at hank.org
>>
>
>
>
> --
> Bill Moseley
> moseley at hank.org
>
> _______________________________________________
> List: http://lists.scsys.co.uk/cgi-bin/mailman/listinfo/dbix-class
> IRC: irc.perl.org#dbix-class
> SVN: http://dev.catalyst.perl.org/repos/bast/DBIx-Class/
> Searchable Archive:
> http://www.grokbase.com/group/dbix-class@lists.scsys.co.uk
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://lists.scsys.co.uk/pipermail/dbix-class/attachments/20101217/1d8=
3a111/attachment.htm