use strict;
use warnings;
+use Scalar::Util ();
use base qw/DBIx::Class/;
-=head1 NAME
+=head1 NAME
DBIx::Class::Relationship::Base - Inter-table relationships
This class provides methods to describe the relationships between the
tables in your database model. These are the "bare bones" relationships
-methods, for predefined ones, look in L<DBIx::Class::Relationship>.
+methods, for predefined ones, look in L<DBIx::Class::Relationship>.
=head1 METHODS
__PACKAGE__->add_relationship('relname', 'Foreign::Class', $cond, $attrs);
-The condition needs to be an SQL::Abstract-style representation of the
-join between the tables. When resolving the condition for use in a JOIN,
-keys using the pseudo-table I<foreign> are resolved to mean "the Table on the
-other side of the relationship", and values using the pseudo-table I<self>
+The condition needs to be an L<SQL::Abstract>-style representation of the
+join between the tables. When resolving the condition for use in a C<JOIN>,
+keys using the pseudo-table C<foreign> are resolved to mean "the Table on the
+other side of the relationship", and values using the pseudo-table C<self>
are resolved to mean "the Table this class is representing". Other
restrictions, such as by value, sub-select and other tables, may also be
-used. Please check your database for JOIN parameter support.
+used. Please check your database for C<JOIN> parameter support.
-For example, if you're creating a rel from Author to Book, where the Book
-table has a column author_id containing the ID of the Author row:
+For example, if you're creating a relationship from C<Author> to C<Book>, where
+the C<Book> table has a column C<author_id> containing the ID of the C<Author>
+row:
{ 'foreign.author_id' => 'self.id' }
-will result in the JOIN clause
+will result in the C<JOIN> clause
- author me JOIN book book ON bar.author_id = me.id
+ author me JOIN book book ON book.author_id = me.id
-You can specify as many foreign => self mappings as necessary. Each key/value
-pair provided in a hashref will be used as ANDed conditions, to add an ORed
-condition, use an arrayref of hashrefs. See the L<SQL::Abstract> documentation
-for more details.
+For multi-column foreign keys, you will need to specify a C<foreign>-to-C<self>
+mapping for each column in the key. For example, if you're creating a
+relationship from C<Book> to C<Edition>, where the C<Edition> table refers to a
+publisher and a type (e.g. "paperback"):
-Valid attributes are as follows:
+ {
+ 'foreign.publisher_id' => 'self.publisher_id',
+ 'foreign.type_id' => 'self.type_id',
+ }
+
+This will result in the C<JOIN> clause:
+
+ book me JOIN edition edition ON edition.publisher_id = me.publisher_id
+ AND edition.type_id = me.type_id
+
+Each key-value pair provided in a hashref will be used as C<AND>ed conditions.
+To add an C<OR>ed condition, use an arrayref of hashrefs. See the
+L<SQL::Abstract> documentation for more details.
+
+In addition to standard result set attributes, the following attributes are also valid:
=over 4
=back
Registers a relationship on the class. This is called internally by
-L<DBIx::Class::ResultSourceProxy> to set up Accessors and Proxies.
+DBIx::Class::ResultSourceProxy to set up Accessors and Proxies.
=cut
=head2 search_related
- $rs->search_related('relname', $cond, $attrs);
+ @objects = $rs->search_related('relname', $cond, $attrs);
+ $objects_rs = $rs->search_related('relname', $cond, $attrs);
Run a search on a related resultset. The search will be restricted to the
item or items represented by the L<DBIx::Class::ResultSet> it was called
return shift->related_resultset(shift)->search(@_);
}
+=head2 search_related_rs
+
+ ( $objects_rs ) = $rs->search_related_rs('relname', $cond, $attrs);
+
+This method works exactly the same as search_related, except that
+it garauntees a restultset, even in list context.
+
+=cut
+
+sub search_related_rs {
+ return shift->related_resultset(shift)->search_rs(@_);
+}
+
=head2 count_related
$obj->count_related('relname', $cond, $attrs);
my $new_obj = $obj->new_related('relname', \%col_data);
Create a new item of the related foreign class. If called on a
-L<DBIx::Class::Manual::Glossary/"Row"> object, it will magically set any
-primary key values into foreign key columns for you. The newly created item
-will not be saved into your storage until you call L<DBIx::Class::Row/insert>
+L<Row|DBIx::Class::Manual::Glossary/"Row"> object, it will magically
+set any foreign key columns of the new object to the related primary
+key columns of the source object for you. The newly created item will
+not be saved into your storage until you call L<DBIx::Class::Row/insert>
on it.
=cut
return $self->search_related($rel)->find(@_);
}
+=head2 find_or_new_related
+
+ my $new_obj = $obj->find_or_new_related('relname', \%col_data);
+
+Find an item of a related class. If none exists, instantiate a new item of the
+related class. The object will not be saved into your storage until you call
+L<DBIx::Class::Row/insert> on it.
+
+=cut
+
+sub find_or_new_related {
+ my $self = shift;
+ return $self->find_related(@_) || $self->new_related(@_);
+}
+
=head2 find_or_create_related
my $new_obj = $obj->find_or_create_related('relname', \%col_data);
Find or create an item of a related class. See
-L<DBIx::Class::ResultSet/"find_or_create"> for details.
+L<DBIx::Class::ResultSet/find_or_create> for details.
=cut
sub find_or_create_related {
my $self = shift;
- return $self->find_related(@_) || $self->create_related(@_);
+ my $obj = $self->find_related(@_);
+ return (defined($obj) ? $obj : $self->create_related(@_));
+}
+
+=head2 update_or_create_related
+
+ my $updated_item = $obj->update_or_create_related('relname', \%col_data, \%attrs?);
+
+Update or create an item of a related class. See
+L<DBIx::Class::ResultSet/update_or_create> for details.
+
+=cut
+
+sub update_or_create_related {
+ my $self = shift;
+ my $rel = shift;
+ return $self->related_resultset($rel)->update_or_create(@_);
}
=head2 set_from_related
"condition for $rel is of type ".
(ref $cond ? ref $cond : 'plain scalar')
) unless ref $cond eq 'HASH';
- my $f_class = $self->result_source->schema->class($rel_obj->{class});
- $self->throw_exception( "Object $f_obj isn't a ".$f_class )
- unless $f_obj->isa($f_class);
+ if (defined $f_obj) {
+ my $f_class = $self->result_source->schema->class($rel_obj->{class});
+ $self->throw_exception( "Object $f_obj isn't a ".$f_class )
+ unless Scalar::Util::blessed($f_obj) and $f_obj->isa($f_class);
+ }
$self->set_columns(
$self->result_source->resolve_condition(
$rel_obj->{cond}, $f_obj, $rel));
return $obj;
}
-1;
+=head2 add_to_$rel
+
+B<Currently only available for C<has_many>, C<many-to-many> and 'multi' type
+relationships.>
+
+=over 4
+
+=item Arguments: ($foreign_vals | $obj), $link_vals?
+
+=back
+
+ my $role = $schema->resultset('Role')->find(1);
+ $actor->add_to_roles($role);
+ # creates a My::DBIC::Schema::ActorRoles linking table row object
+
+ $actor->add_to_roles({ name => 'lead' }, { salary => 15_000_000 });
+ # creates a new My::DBIC::Schema::Role row object and the linking table
+ # object with an extra column in the link
+
+Adds a linking table object for C<$obj> or C<$foreign_vals>. If the first
+argument is a hash reference, the related object is created first with the
+column values in the hash. If an object reference is given, just the linking
+table object is created. In either case, any additional column values for the
+linking table object can be specified in C<$link_vals>.
+
+=head2 set_$rel
+
+B<Currently only available for C<many-to-many> relationships.>
+
+=over 4
+
+=item Arguments: (\@hashrefs | \@objs)
+
+=back
+
+ my $actor = $schema->resultset('Actor')->find(1);
+ my @roles = $schema->resultset('Role')->search({ role =>
+ { '-in' -> ['Fred', 'Barney'] } } );
+
+ $actor->set_roles(\@roles);
+ # Replaces all of $actor's previous roles with the two named
+
+Replace all the related objects with the given reference to a list of
+objects. This does a C<delete> B<on the link table resultset> to remove the
+association between the current object and all related objects, then calls
+C<add_to_$rel> repeatedly to link all the new objects.
+
+Note that this means that this method will B<not> delete any objects in the
+table on the right side of the relation, merely that it will delete the link
+between them.
+
+Due to a mistake in the original implementation of this method, it will also
+accept a list of objects or hash references. This is B<deprecated> and will be
+removed in a future version.
+
+=head2 remove_from_$rel
+
+B<Currently only available for C<many-to-many> relationships.>
+
+=over 4
+
+=item Arguments: $obj
+
+=back
+
+ my $role = $schema->resultset('Role')->find(1);
+ $actor->remove_from_roles($role);
+ # removes $role's My::DBIC::Schema::ActorRoles linking table row object
+
+Removes the link between the current object and the related object. Note that
+the related object itself won't be deleted unless you call ->delete() on
+it. This method just removes the link between the two objects.
=head1 AUTHORS
=cut
+1;