=head1 SYNOPSIS
+ MyDB::Schema::Actor->has_many('actorroles' => 'MyDB::Schema::ActorRole',
+ 'actor');
+ MyDB::Schema::Role->has_many('actorroles' => 'MyDB::Schema::ActorRole',
+ 'role');
+ MyDB::Schema::ActorRole->belongs_to('role' => 'MyDB::Schema::Role');
+ MyDB::Schema::ActorRole->belongs_to('actor' => 'MyDB::Schema::Actor');
+
+ MyDB::Schema::Role->many_to_many('actors' => 'actorroles', 'actor');
+ MyDB::Schema::Actor->many_to_many('roles' => 'actorroles', 'role');
+
+ $schema->resultset('Actor')->roles();
+ $schema->resultset('Role')->search_related('actors', { Name => 'Fred' });
+ $schema->resultset('ActorRole')->add_to_role({ Name => 'Sherlock Holmes'});
+
+See L<DBIx::Class::Manual::Cookbook> for more.
+
=head1 DESCRIPTION
This class provides methods to set up relationships between the tables
all without needing multiple fetches.
Only the helper methods for setting up standard relationship types
-are documented here. For the basic, lower-level methods, see
+are documented here. For the basic, lower-level methods, and a description
+of all the useful *_related methods that you get for free, see
L<DBIx::Class::Relationship::Base>.
=head1 METHODS
=head2 belongs_to
# in a Book class (where Author has many Books)
- My::DBIC::Schema::Book->belongs_to(author => 'Author');
+ My::DBIC::Schema::Book->belongs_to(author => 'My::DBIC::Schema::Author');
my $author_obj = $obj->author;
$obj->author($new_author_obj);
=head2 has_many
# in an Author class (where Author has many Books)
- My::DBIC::Schema::Author->has_many(books => 'Book', 'author');
+ My::DBIC::Schema::Author->has_many(books => 'My::DBIC::Schema::Book', 'author');
my $booklist = $obj->books;
my $booklist = $obj->books({
name => { LIKE => '%macaroni%' },
columns. You should pass the name of the column in the foreign class as the
$cond argument, or specify a complete join condition.
+As well as the accessor method, a method named C<< add_to_<relname> >>
+will also be added to your Row items, this allows you to insert new
+related items, using the same mechanism as in L<DBIx::Class::Relationship::Base/"create_related">.
+
If you delete an object in a class with a C<has_many> relationship, all
related objects will be deleted as well. However, any database-level
cascade or restrict will take precedence.
=head2 might_have
- My::DBIC::Schema::Author->might_have(pseudonym => 'Pseudonyms');
+ My::DBIC::Schema::Author->might_have(pseudonym =>
+ 'My::DBIC::Schema::Pseudonyms');
my $pname = $obj->pseudonym; # to get the Pseudonym object
Creates an optional one-to-one relationship with a class, where the foreign
=head2 has_one
- My::DBIC::Schema::Book->has_one(isbn => ISBN);
+ My::DBIC::Schema::Book->has_one(isbn => 'My::DBIC::Schema::ISBN');
my $isbn_obj = $obj->isbn;
Creates a one-to-one relationship with another class. This is just like
=head2 many_to_many
- My::DBIC::Schema::Actor->many_to_many( roles => 'actor_roles', 'Roles' );
+ My::DBIC::Schema::Actor->has_many( actor_roles =>
+ 'My::DBIC::Schema::ActorRoles',
+ 'actor' );
+ My::DBIC::Schema::ActorRoles->belongs_to( role =>
+ 'My::DBIC::Schema::Role' );
+ My::DBIC::Schema::ActorRoles->belongs_to( actor =>
+ 'My::DBIC::Schema::Actor' );
+
+ My::DBIC::Schema::Actor->many_to_many( roles => 'actor_roles',
+ 'My::DBIC::Schema::Roles' );
...
Creates an accessor bridging two relationships; not strictly a relationship
in its own right, although the accessor will return a resultset or collection
of objects just as a has_many would.
+To use many_to_many, existing relationships from the original table to the link
+table, and from the link table to the end table must already exist, these
+relation names are then used in the many_to_many call.
=cut