Am 30.06.2009 um 18:10 schrieb David Ihnen:
Rob Kinyon wrote:
Now, if someone can provide a solid use-case, then I'll be onboard.
But, adding features for the sake of adding features is how you end
up
with a crappy API.
Rob
Lets see if I can argue the use case. I tripped over this
limitation and I *think* it was when I was doing this part of the
implementation
I have a data structure formed like so;
Each client has a set of users. Clients are enumerated in a
separate table, foreign keyed from the user table. They use the
same structure for their hierarchy.
Each user record thus has a client value, as well as a left and a
right value. The data structure is maintained so that the left and
right numbers are sequential - supervisor has left/right of 1/4, his
single subordinate has left/right of 2/3 - on insert of another
subordinate, supervisor becomes 1/6 and the second subordinate is
4/5. A sub-subordinate on the second user would be 5/6, moving his
super to 4/7 and the top super to 1/8.
This allows an arbitrary depth of organizational structure but
allows straightforward queries for inheritance/supervisor permission
checks.
If the client is the same and their left and/or right are between
your own, they are your subordinate.
If the client is the same and you are between somebody else's left
and right, they are your supervisor.
The complication comes when I want to describe the relationships
'users subordinates' or 'users supervisors'. The constraint of 'in
the same client' is part of the join term - not just a where clause.
So I'd like to say something like this in my user model class:
package DB:Schema::samp_user;
__PACKAGE__->has_many('subordinates' => 'DB::Schema::samp_user',
{ 'subordinates.client' => 'samp_user.client', 'subordinates.lft' =>
{ '-between' => [ 'samp_user.lft', 'samp_user.right' ] } } );
But I can't, because you can't specify complicated join conditions
like that.
So what do you think, is that a solid use case?
David
Hi David,
work is in progress to add this feature to DBIC. The proposed syntax
can be found here: http://dev.catalyst.perl.org/svnweb/bast/revision/?rev=6890
feel free to add your own test case to this branch (http://dev.catalyst.perl.org/repos/bast/DBIx-Class/0.08/branches/extended_rels/
)!
cheers,
moritz
_______________________________________________
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
