use strict;
use warnings;
+use Scalar::Util ();
use base qw/DBIx::Class/;
-__PACKAGE__->mk_classdata('_relationships', { } );
-
-=head1 NAME
+=head1 NAME
DBIx::Class::Relationship::Base - Inter-table relationships
=head1 DESCRIPTION
-This class handles relationships between the tables in your database
-model. It allows your to set up relationships, and to perform joins
-on searches.
+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>.
=head1 METHODS
=head2 add_relationship
+=over 4
+
+=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. For example, if you're creating a rel from Foo to Bar,
+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 C<JOIN> parameter support.
+
+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' }
- { 'foreign.foo_id' => 'self.id' }
+will result in the C<JOIN> clause
-will result in the JOIN clause
+ author me JOIN book book ON book.author_id = me.id
- foo me JOIN bar bar ON bar.foo_id = me.id
+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"):
+
+ {
+ 'foreign.publisher_id' => 'self.publisher_id',
+ 'foreign.type_id' => 'self.type_id',
+ }
-You can specify as many foreign => self mappings as necessary.
+This will result in the C<JOIN> clause:
-Valid attributes are as follows:
+ 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
=item proxy
-An arrayref containing a list of accessors in the foreign class to proxy in
+An arrayref containing a list of accessors in the foreign class to create in
the main class. If, for example, you do the following:
- __PACKAGE__->might_have(bar => 'Bar', undef, { proxy => [ qw/margle/ ] });
+ MyDB::Schema::CD->might_have(liner_notes => 'MyDB::Schema::LinerNotes',
+ undef, {
+ proxy => [ qw/notes/ ],
+ });
-Then, assuming Bar has an accessor named margle, you can do:
+Then, assuming MyDB::Schema::LinerNotes has an accessor named notes, you can do:
- my $obj = Foo->find(1);
- $obj->margle(10); # set margle; Bar object is created if it doesn't exist
+ my $cd = MyDB::Schema::CD->find(1);
+ $cd->notes('Notes go here'); # set notes -- LinerNotes object is
+ # created if it doesn't exist
=item accessor
a column accessor). For C<multi> accessors, an add_to_* method is also
created, which calls C<create_related> for the relationship.
+=item is_foreign_key_constraint
+
+If you are using L<SQL::Translator> to create SQL for you and you find that it
+is creating constraints where it shouldn't, or not creating them where it
+should, set this attribute to a true or false value to override the detection
+of when to create constraints.
+
+=item on_delete / on_update
+
+If you are using L<SQL::Translator> to create SQL for you, you can use these
+attributes to explicitly set the desired C<ON DELETE> or C<ON UPDATE> constraint
+type. If not supplied the SQLT parser will attempt to infer the constraint type by
+interrogating the attributes of the B<opposite> relationship. For any 'multi'
+relationship with C<< cascade_delete => 1 >>, the corresponding belongs_to
+relationship will be created with an C<ON DELETE CASCADE> constraint. For any
+relationship bearing C<< cascade_copy => 1 >> the resulting belongs_to constraint
+will be C<ON UPDATE CASCADE>. If you wish to disable this autodetection, and just
+use the RDBMS' default constraint type, pass C<< on_delete => undef >> or
+C<< on_delete => '' >>, and the same for C<on_update> respectively.
+
+=item is_deferrable
+
+Tells L<SQL::Translator> that the foreign key constraint it creates should be
+deferrable. In other words, the user may request that the constraint be ignored
+until the end of the transaction. Currently, only the PostgreSQL producer
+actually supports this.
+
+=item add_fk_index
+
+Tells L<SQL::Translator> to add an index for this constraint. Can also be
+specified globally in the args to L<DBIx::Class::Schema/deploy> or
+L<DBIx::Class::Schema/create_ddl_dir>. Default is on, set to 0 to disable.
+
=back
=head2 register_relationship
-=head3 Arguments: ($relname, $rel_info)
+=over 4
+
+=item Arguments: $relname, $rel_info
+
+=back
-Registers a relationship on the class
+Registers a relationship on the class. This is called internally by
+DBIx::Class::ResultSourceProxy to set up Accessors and Proxies.
=cut
sub register_relationship { }
+=head2 related_resultset
+
+=over 4
+
+=item Arguments: $relationship_name
+
+=item Return Value: $related_resultset
+
+=back
+
+ $rs = $cd->related_resultset('artist');
+
+Returns a L<DBIx::Class::ResultSet> for the relationship named
+$relationship_name.
+
+=cut
+
+sub related_resultset {
+ my $self = shift;
+ $self->throw_exception("Can't call *_related as class methods")
+ unless ref $self;
+ my $rel = shift;
+ my $rel_obj = $self->relationship_info($rel);
+ $self->throw_exception( "No such relationship ${rel}" )
+ unless $rel_obj;
+
+ return $self->{related_resultsets}{$rel} ||= do {
+ my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
+ $attrs = { %{$rel_obj->{attrs} || {}}, %$attrs };
+
+ $self->throw_exception( "Invalid query: @_" )
+ if (@_ > 1 && (@_ % 2 == 1));
+ my $query = ((@_ > 1) ? {@_} : shift);
+
+ 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 {
+ 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};
+ }
+ }
+ $query = ($query ? { '-and' => [ $cond, $query ] } : $cond);
+ $self->result_source->related_source($rel)->resultset->search(
+ $query, $attrs
+ );
+ };
+}
+
=head2 search_related
- My::Table->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
+upon. This method can be called on a ResultSet, a Row or a ResultSource class.
=cut
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);
+Returns the count of all the items in the related resultset, restricted by the
+current item or where conditions. Can be called on a
+L<DBIx::Class::Manual::Glossary/"ResultSet"> or a
+L<DBIx::Class::Manual::Glossary/"Row"> object.
+
=cut
sub count_related {
return $self->search_related(@_)->count;
}
+=head2 new_related
+
+ my $new_obj = $obj->new_related('relname', \%col_data);
+
+Create a new item of the related foreign class. If called on a
+L<Row|DBIx::Class::Manual::Glossary/"Row"> object, it will magically
+set any foreign key columns of the new object to the related primary
+key columns of the source object for you. The newly created item will
+not be saved into your storage until you call L<DBIx::Class::Row/insert>
+on it.
+
+=cut
+
+sub new_related {
+ my ($self, $rel, $values, $attrs) = @_;
+ return $self->search_related($rel)->new($values, $attrs);
+}
+
=head2 create_related
- My::Table->create_related('relname', \%col_data);
+ my $new_obj = $obj->create_related('relname', \%col_data);
+
+Creates a new item, similarly to new_related, and also inserts the item's data
+into your storage medium. See the distinction between C<create> and C<new>
+in L<DBIx::Class::ResultSet> for details.
=cut
return $obj;
}
-=head2 new_related
+=head2 find_related
+
+ my $found_item = $obj->find_related('relname', @pri_vals | \%pri_vals);
- My::Table->new_related('relname', \%col_data);
+Attempt to find a related object using its primary key or unique constraints.
+See L<DBIx::Class::ResultSet/find> for details.
=cut
-sub new_related {
- my ($self, $rel, $values, $attrs) = @_;
- return $self->search_related($rel)->new($values, $attrs);
+sub find_related {
+ my $self = shift;
+ my $rel = shift;
+ return $self->search_related($rel)->find(@_);
}
-=head2 find_related
+=head2 find_or_new_related
+
+ my $new_obj = $obj->find_or_new_related('relname', \%col_data);
- My::Table->find_related('relname', @pri_vals | \%pri_vals);
+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_related {
+sub find_or_new_related {
my $self = shift;
- my $rel = shift;
- return $self->search_related($rel)->find(@_);
+ my $obj = $self->find_related(@_);
+ return defined $obj ? $obj : $self->new_related(@_);
}
=head2 find_or_create_related
- My::Table->find_or_create_related('relname', \%col_data);
+ 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.
=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
- My::Table->set_from_related('relname', $rel_obj);
+ $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.
=cut
my $rel_obj = $self->relationship_info($rel);
$self->throw_exception( "No such relationship ${rel}" ) unless $rel_obj;
my $cond = $rel_obj->{cond};
- $self->throw_exception( "set_from_related can only handle a hash condition; the "
- ."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);
+ $self->throw_exception(
+ "set_from_related can only handle a hash condition; the ".
+ "condition for $rel is of type ".
+ (ref $cond ? ref $cond : 'plain scalar')
+ ) unless ref $cond eq 'HASH';
+ 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));
=head2 update_from_related
- My::Table->update_from_related('relname', $rel_obj);
+ $book->update_from_related('author', $author_obj);
+
+The same as L</"set_from_related">, but the changes are immediately updated
+in storage.
=cut
=head2 delete_related
- My::Table->delete_related('relname', $cond, $attrs);
+ $obj->delete_related('relname', $cond, $attrs);
+
+Delete any related item subject to the given conditions.
=cut
return $obj;
}
-1;
+=head2 add_to_$rel
-=head2 related_resultset($name)
+B<Currently only available for C<has_many>, C<many-to-many> and 'multi' type
+relationships.>
-Returns a L<DBIx::Class::ResultSet> for the relationship named $name.
+=over 4
- $rs = My::Table->related_resultset('related_table');
+=item Arguments: ($foreign_vals | $obj), $link_vals?
-=cut
+=back
-sub related_resultset {
- my $self = shift;
- $self->throw_exception("Can't call *_related as class methods") unless ref $self;
- my $rel = shift;
- $self->{related_resultsets} ||= {};
- #use Data::Dumper; warn "related_resultsets: ", Dumper $self->{related_resultsets};
- my $resultsets = $self->{related_resultsets};
- if( !exists $resultsets->{$rel} ) {
+ my $role = $schema->resultset('Role')->find(1);
+ $actor->add_to_roles($role);
+ # creates a My::DBIC::Schema::ActorRoles linking table row object
- #warn "creating related resultset for relation '$rel'", \$self;
- my $source = $self->result_source;
- # if relation exists but resultset doesn't, create the resultset
+ $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
- my $attrs = { };
- if (@_ > 1 && ref $_[$#_] eq 'HASH') {
- $attrs = { %{ pop(@_) } };
- }
-
- my $rel_obj = $self->relationship_info($rel);
- $self->throw_exception( "No such relationship ${rel}" ) unless $rel_obj;
- $attrs = { %{$rel_obj->{attrs} || {}}, %{$attrs || {}} };
+Adds a linking table object for C<$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>.
- $self->throw_exception( "Invalid query: @_" ) if (@_ > 1 && (@_ % 2 == 1));
- my $query = ((@_ > 1) ? {@_} : shift);
+=head2 set_$rel
- my ($cond) = $self->result_source->resolve_condition($rel_obj->{cond}, $rel, $self);
- if (ref $cond eq 'ARRAY') {
- $cond = [ map { my %hash;
- foreach my $key (keys %{$_}) {
- unless ($key =~ m/\./) {
- $hash{"me.$key"} = $_->{$key};
- } else {
- $hash{$key} = $_->{$key};
- }
- }; \%hash; } @$cond ];
- } else {
- foreach my $key (keys %$cond) {
- unless ($key =~ m/\./) {
- $cond->{"me.$key"} = delete $cond->{$key};
- }
- }
- }
- $query = ($query ? { '-and' => [ $cond, $query ] } : $cond);
- #use Data::Dumper; warn Dumper($cond);
- #warn $rel_obj->{class}." $meth $cond ".join(', ', @{$attrs->{bind}||[]});
- $resultsets->{$rel} =
- $self->result_source->related_source($rel)->resultset->search($query, $attrs);
- }
- return $resultsets->{$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