I sent this question to the Class::DBI list last week, but didn't get
any replies so I thought I'd ask here too. Can anyone help me out?
Kake
----- Forwarded message from Kate L Pugh <[EMAIL PROTECTED]> -----
Hello. I only started using Class::DBI last week so please don't
laugh if this is a stupid question.
I'm using Class::DBI::Join to relate dealers (of the art kind) to
categories. So I've got a (many-to-many) table that relates dealer
IDs and category IDs, and a Categorisation class that subclasses
Class::DBI::Join so I can put dealers in categories and get them out
again. The thing I need to add is support for the 'importance' column
in that table - some dealers are major dealers in a category, others
only occasionally stock items from that category. Now as it stands I
can do:
$category->add_dealer( dealer => $minor_dealer, importance => 2 );
and the information goes in the table, and I can get all the dealers in
a category with:
@dealers = Categorisation->join( $category );
but I want to be able to do:
@dealers = Categorisation->join( $category, importance => 1 );
to get just the major dealers, and I can't work out what the
recommended way to do this is. I made a patch to Class::DBI::Join
(attached with tests) to make the line above Just Work, but I'm sure
I've missed something that makes this a bad idea.
Help?
Kake
diff -pubr Class-DBI-Join-0.03/lib/Class/DBI/Join.pm
class-dbi-join/lib/Class/DBI/Join.pm
--- Class-DBI-Join-0.03/lib/Class/DBI/Join.pm 2002-04-17 16:10:16.000000000 +0100
+++ class-dbi-join/lib/Class/DBI/Join.pm 2003-02-12 12:27:24.000000000 +0000
@@ -24,7 +24,8 @@ Class::DBI::Join - many-to-many relation
# Given a join table like:
# CREATE TABLE films_and_actors (
# film_id INTEGER REFERENCES films,
- # actor_id INTEGER REFERENCES actors
+ # actor_id INTEGER REFERENCES actors,
+ # as_name VARCHAR(80)
# );
# And assuming Film and Actor are Class::DBI subclasses.
Roles->table('films_and_actors');
@@ -40,6 +41,7 @@ Class::DBI::Join - many-to-many relation
my $btaste = Film->retrieve('Bad Taste');
my @roles = Roles->join($btaste);
+ my @alien_roles = Roles->join($btaste, as_name => '3rd Class Alien');
=head1 DESCRIPTION
@@ -57,8 +59,17 @@ Class::DBI::Join adds the following meth
=item I<join>
+ # Find all roles in the film Bad Taste.
my @roles = Roles->join($btaste);
+ # Or just those in which the actors are playing aliens.
+ my @alien_roles = Roles->join($btaste, as_name => '3rd Class Alien');
+
+The first argument to C<join> should be the object whose relations you
+want to find. Any other arguments will be passed straight through to
+the C<search> method of L<Class::DBI>, so you can provide information
+here to construct additional WHERE clauses.
+
=cut
__PACKAGE__->set_sql('ManyToMany', <<SQL);
@@ -68,10 +79,10 @@ WHERE %s = ?
SQL
sub join {
- my($class, $one) = @_;
+ my($class, $one, @args) = @_;
my $hasa_cols = __hasa_cols($class);
- return $class->search( $hasa_cols->{ref $one} => $one->id );
+ return $class->search( $hasa_cols->{ref $one} => $one->id, @args );
}
diff -pubr Class-DBI-Join-0.03/t/Join.t class-dbi-join/t/Join.t
--- Class-DBI-Join-0.03/t/Join.t 2002-04-16 21:09:03.000000000 +0100
+++ class-dbi-join/t/Join.t 2003-02-12 12:20:39.000000000 +0000
@@ -1,6 +1,6 @@
#!/usr/bin/perl -w
-use Test::More tests => 11;
+use Test::More tests => 13;
require_ok('Class::DBI::Join');
use lib qw(t/lib/);
@@ -60,6 +60,12 @@ my $btaste = Film->retrieve('Bad Taste')
my @bt_roles = Roles->join($btaste);
is( @bt_roles, 6 );
+my @aliens = Roles->join($btaste, as_name => '3rd Class Alien');
+is( @aliens, 2, 'join works with extra where clause' );
+my @alien_actors = sort map { $_->actor->name } @aliens;
+is_deeply( \@alien_actors, ['Craig Smith (I)', 'Terry Potter'],
+ '...returns the right things too' );
+
my $pj = Actor->retrieve('Peter Jackson');
my @pj_roles = Roles->join($pj);
is( @pj_roles, 4 );
----- End forwarded message -----
