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
=over 4
-=item Arguments: ('relname', 'Foreign::Class', $cond, $attrs)
+=item Arguments: 'relname', 'Foreign::Class', $cond, $attrs
=back
__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
a column accessor). For C<multi> accessors, an add_to_* method is also
created, which calls C<create_related> for the relationship.
+=item is_foreign_key_constraint
+
+If you are using L<SQL::Translator> to create SQL for you and you find that it
+is creating constraints where it shouldn't, or not creating them where it
+should, set this attribute to a true or false value to override the detection
+of when to create constraints.
+
+=item on_delete / on_update
+
+If you are using L<SQL::Translator> to create SQL for you, you can use these
+attributes to explicitly set the desired C<ON DELETE> or C<ON UPDATE> constraint
+type. If not supplied the SQLT parser will attempt to infer the constraint type by
+interrogating the attributes of the B<opposite> relationship. For any 'multi'
+relationship with C<< cascade_delete => 1 >>, the corresponding belongs_to
+relationship will be created with an C<ON DELETE CASCADE> constraint. For any
+relationship bearing C<< cascade_copy => 1 >> the resulting belongs_to constraint
+will be C<ON UPDATE CASCADE>. If you wish to disable this autodetection, and just
+use the RDBMS' default constraint type, pass C<< on_delete => undef >> or
+C<< on_delete => '' >>, and the same for C<on_update> respectively.
+
+=item is_deferrable
+
+Tells L<SQL::Translator> that the foreign key constraint it creates should be
+deferrable. In other words, the user may request that the constraint be ignored
+until the end of the transaction. Currently, only the PostgreSQL producer
+actually supports this.
+
+=item add_fk_index
+
+Tells L<SQL::Translator> to add an index for this constraint. Can also be
+specified globally in the args to L<DBIx::Class::Schema/deploy> or
+L<DBIx::Class::Schema/create_ddl_dir>. Default is on, set to 0 to disable.
+
=back
=head2 register_relationship
=over 4
-=item Arguments: ($relname, $rel_info)
+=item Arguments: $relname, $rel_info
=back
Registers a relationship on the class. This is called internally by
-L<DBIx::Class::ResultSourceProxy> to set up Accessors and Proxies.
+DBIx::Class::ResultSourceProxy to set up Accessors and Proxies.
=cut
=over 4
-=item Arguments: ($relationship_name)
+=item Arguments: $relationship_name
-=item Returns: $related_resultset
+=item Return Value: $related_resultset
=back
if (@_ > 1 && (@_ % 2 == 1));
my $query = ((@_ > 1) ? {@_} : shift);
- my $cond = $self->result_source->resolve_condition(
+ my $source = $self->result_source;
+ my $cond = $source->resolve_condition(
$rel_obj->{cond}, $rel, $self
);
+ if ($cond eq $DBIx::Class::ResultSource::UNRESOLVABLE_CONDITION) {
+ my $reverse = $source->reverse_relationship_info($rel);
+ foreach my $rev_rel (keys %$reverse) {
+ $attrs->{related_objects}{$rev_rel} = $self;
+ Scalar::Util::weaken($attrs->{related_object}{$rev_rel});
+ }
+ }
if (ref $cond eq 'ARRAY') {
- $cond = [ map { my $hash;
- foreach my $key (keys %$_) {
- my $newkey = $key =~ /\./ ? "me.$key" : $key;
- $hash->{$newkey} = $_->{$key};
- }; $hash } @$cond ];
- } else {
+ $cond = [ map {
+ if (ref $_ eq 'HASH') {
+ my $hash;
+ foreach my $key (keys %$_) {
+ my $newkey = $key =~ /\./ ? "me.$key" : $key;
+ $hash->{$newkey} = $_->{$key};
+ }
+ $hash;
+ } else {
+ $_;
+ }
+ } @$cond ];
+ } elsif (ref $cond eq 'HASH') {
foreach my $key (grep { ! /\./ } keys %$cond) {
$cond->{"me.$key"} = delete $cond->{$key};
}
=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 guarantees 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;
+ my $obj = $self->find_related(@_);
+ return defined $obj ? $obj : $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
$book->set_from_related('author', $author_obj);
+ $book->author($author_obj); ## same thing
Set column values on the current object, using related values from the given
related object. This is used to associate previously separate objects, for
example, to set the correct author for a book, find the Author object, then
call set_from_related on the book.
+This is called internally when you pass existing objects as values to
+L<DBIx::Class::ResultSet/create>, or pass an object to a belongs_to acessor.
+
The columns are only set in the local copy of the object, call L</update> to
set them in the storage.
"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;
projects / dbsrgits/DBIx-Class.git / blobdiff