1 package DBIx::Class::Relationship::Base;
6 use base qw/DBIx::Class/;
8 __PACKAGE__->mk_classdata('_relationships', { } );
12 DBIx::Class::Relationship::Base - Inter-table relationships
18 This class handles relationships between the tables in your database
19 model. It allows your to set up relationships, and to perform joins
24 =head2 add_relationship
26 __PACKAGE__->add_relationship('relname', 'Foreign::Class', $cond, $attrs);
28 The condition needs to be an SQL::Abstract-style representation of the
29 join between the tables. For example, if you're creating a rel from Foo to Bar,
31 { 'foreign.foo_id' => 'self.id' }
33 will result in the JOIN clause
35 foo me JOIN bar bar ON bar.foo_id = me.id
37 You can specify as many foreign => self mappings as necessary.
39 Valid attributes are as follows:
45 Explicitly specifies the type of join to use in the relationship. Any SQL
46 join type is valid, e.g. C<LEFT> or C<RIGHT>. It will be placed in the SQL
47 command immediately before C<JOIN>.
51 An arrayref containing a list of accessors in the foreign class to proxy in
52 the main class. If, for example, you do the following:
54 __PACKAGE__->might_have(bar => 'Bar', undef, { proxy => qw[/ margle /] });
56 Then, assuming Bar has an accessor named margle, you can do:
58 my $obj = Foo->find(1);
59 $obj->margle(10); # set margle; Bar object is created if it doesn't exist
63 Specifies the type of accessor that should be created for the relationship.
64 Valid values are C<single> (for when there is only a single related object),
65 C<multi> (when there can be many), and C<filter> (for when there is a single
66 related object, but you also want the relationship accessor to double as
67 a column accessor). For C<multi> accessors, an add_to_* method is also
68 created, which calls C<create_related> for the relationship.
76 My::Table->search_related('relname', $cond, $attrs);
82 die "Can't call *_related as class methods" unless ref $self;
85 if (@_ > 1 && ref $_[$#_] eq 'HASH') {
86 $attrs = { %{ pop(@_) } };
88 my $rel_obj = $self->relationship_info($rel);
89 $self->throw( "No such relationship ${rel}" ) unless $rel_obj;
90 $attrs = { %{$rel_obj->{attrs} || {}}, %{$attrs || {}} };
92 $self->throw( "Invalid query: @_" ) if (@_ > 1 && (@_ % 2 == 1));
93 my $query = ((@_ > 1) ? {@_} : shift);
95 my ($cond) = $self->result_source->resolve_condition($rel_obj->{cond}, $rel, $self);
96 $query = ($query ? { '-and' => [ $cond, $query ] } : $cond);
97 #use Data::Dumper; warn Dumper($cond);
98 #warn $rel_obj->{class}." $meth $cond ".join(', ', @{$attrs->{bind}||[]});
99 return $self->result_source->related_source($rel
100 )->resultset->search($query, $attrs);
105 My::Table->count_related('relname', $cond, $attrs);
111 return $self->search_related(@_)->count;
114 =head2 create_related
116 My::Table->create_related('relname', \%col_data);
123 return $self->search_related($rel)->create(@_);
128 My::Table->new_related('relname', \%col_data);
133 my ($self, $rel, $values, $attrs) = @_;
134 return $self->search_related($rel)->new($values, $attrs);
139 My::Table->find_related('relname', @pri_vals | \%pri_vals);
146 return $self->search_related($rel)->find(@_);
149 =head2 find_or_create_related
151 My::Table->find_or_create_related('relname', \%col_data);
155 sub find_or_create_related {
157 return $self->find_related(@_) || $self->create_related(@_);
160 =head2 set_from_related
162 My::Table->set_from_related('relname', $rel_obj);
166 sub set_from_related {
167 my ($self, $rel, $f_obj) = @_;
168 my $rel_obj = $self->relationship_info($rel);
169 $self->throw( "No such relationship ${rel}" ) unless $rel_obj;
170 my $cond = $rel_obj->{cond};
171 $self->throw( "set_from_related can only handle a hash condition; the "
172 ."condition for $rel is of type ".(ref $cond ? ref $cond : 'plain scalar'))
173 unless ref $cond eq 'HASH';
174 my $f_class = $self->result_source->schema->class($rel_obj->{class});
175 $self->throw( "Object $f_obj isn't a ".$f_class )
176 unless $f_obj->isa($f_class);
177 foreach my $key (keys %$cond) {
178 next if ref $cond->{$key}; # Skip literals and complex conditions
179 $self->throw("set_from_related can't handle $key as key")
180 unless $key =~ m/^foreign\.([^\.]+)$/;
181 my $val = $f_obj->get_column($1);
182 $self->throw("set_from_related can't handle ".$cond->{$key}." as value")
183 unless $cond->{$key} =~ m/^self\.([^\.]+)$/;
184 $self->set_column($1 => $val);
189 =head2 update_from_related
191 My::Table->update_from_related('relname', $rel_obj);
195 sub update_from_related {
197 $self->set_from_related(@_);
201 =head2 delete_related
203 My::Table->delete_related('relname', $cond, $attrs);
209 return $self->search_related(@_)->delete;
216 Matt S. Trout <mst@shadowcatsystems.co.uk>
220 You may distribute this code under the same terms as Perl itself.