NAME

DBIx::Class::Relationship::Base - Inter-table relationships

SYNOPSIS

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.

METHODS

add_relationship

  __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,

  { 'foreign.foo_id' => 'self.id' }

will result in the JOIN clause

  foo me JOIN bar bar ON bar.foo_id = me.id

You can specify as many foreign => self mappings as necessary.

Valid attributes are as follows:

join_type

Explicitly specifies the type of join to use in the relationship. Any SQL join type is valid, e.g. LEFT or RIGHT. It will be placed in the SQL command immediately before JOIN.

proxy

An arrayref containing a list of accessors in the foreign class to proxy in the main class. If, for example, you do the following:

  __PACKAGE__->might_have(bar => 'Bar', undef, { proxy => [ qw/margle/ ] });
  

Then, assuming Bar has an accessor named margle, you can do:

  my $obj = Foo->find(1);
  $obj->margle(10); # set margle; Bar object is created if it doesn't exist
  

accessor

Specifies the type of accessor that should be created for the relationship. Valid values are single (for when there is only a single related object), multi (when there can be many), and filter (for when there is a single related object, but you also want the relationship accessor to double as a column accessor). For multi accessors, an add_to_* method is also created, which calls create_related for the relationship.

register_relationship($relname, $rel_info)

Registers a relationship on the class

search_related

  My::Table->search_related('relname', $cond, $attrs);

count_related

  $obj->count_related('relname', $cond, $attrs);

create_related

  My::Table->create_related('relname', \%col_data);

new_related

  My::Table->new_related('relname', \%col_data);

find_related

  My::Table->find_related('relname', @pri_vals | \%pri_vals);

find_or_create_related

  My::Table->find_or_create_related('relname', \%col_data);

set_from_related

  My::Table->set_from_related('relname', $rel_obj);

update_from_related

  My::Table->update_from_related('relname', $rel_obj);

delete_related

  My::Table->delete_related('relname', $cond, $attrs);

AUTHORS

Matt S. Trout <mst@shadowcatsystems.co.uk>

LICENSE

You may distribute this code under the same terms as Perl itself.

cpanm DBIx::Class

perl -MCPAN -e shell
install DBIx::Class