1 package DBIx::Class::Relationship;
6 use base qw/Class::Data::Inheritable/;
8 __PACKAGE__->mk_classdata('_relationships', { } );
12 DBIx::Class::Relationship - 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
28 sub add_relationship {
29 my ($class, $rel, $f_class, $cond, $attrs) = @_;
30 die "Can't create relationship without join condition" unless $cond;
33 my %rels = %{ $class->_relationships };
34 $rels{$rel} = { class => $f_class,
37 $class->_relationships(\%rels);
38 #warn %{$f_class->_columns};
39 return unless eval { %{$f_class->_columns}; }; # Foreign class not loaded
40 my %join = (%$attrs, _action => 'join',
41 _aliases => { 'self' => 'me', 'foreign' => $rel },
42 _classes => { 'me' => $class, $rel => $f_class });
43 eval { $class->_cond_resolve($cond, \%join) };
44 $class->throw("Error creating relationship $rel: $@") if $@;
48 my ($self, $attrs, $key) = @_;
49 my $action = $attrs->{_action} || '';
50 if ($action eq 'convert') {
51 unless ($key =~ s/^foreign\.//) {
52 $self->throw("Unable to convert relationship to WHERE clause: invalid key ${key}");
55 } elsif ($action eq 'join') {
56 my ($type, $field) = split(/\./, $key);
57 if (my $alias = $attrs->{_aliases}{$type}) {
58 my $class = $attrs->{_classes}{$alias};
59 $self->throw("Unknown column $field on $class as $alias")
60 unless exists $class->_columns->{$field};
61 return join('.', $alias, $field);
63 $self->throw( "Unable to resolve type ${type}: only have aliases for ".
64 join(', ', keys %{$attrs->{_aliases} || {}}) );
67 return $self->NEXT::ACTUAL::_cond_key($attrs, $key);
71 my ($self, $attrs, $key, $value) = @_;
72 my $action = $attrs->{_action} || '';
73 if ($action eq 'convert') {
74 unless ($value =~ s/^self\.//) {
75 $self->throw( "Unable to convert relationship to WHERE clause: invalid value ${value}" );
77 unless ($self->_columns->{$value}) {
78 $self->throw( "Unable to convert relationship to WHERE clause: no such accessor ${value}" );
80 push(@{$attrs->{bind}}, $self->get_column($value));
82 } elsif ($action eq 'join') {
83 my ($type, $field) = split(/\./, $value);
84 if (my $alias = $attrs->{_aliases}{$type}) {
85 my $class = $attrs->{_classes}{$alias};
86 $self->throw("Unknown column $field on $class as $alias")
87 unless exists $class->_columns->{$field};
88 return join('.', $alias, $field);
90 $self->throw( "Unable to resolve type ${type}: only have aliases for ".
91 join(', ', keys %{$attrs->{_aliases} || {}}) );
95 return $self->NEXT::ACTUAL::_cond_value($attrs, $key, $value)
102 if (@_ > 1 && ref $_[$#_] eq 'HASH') {
103 $attrs = { %{ pop(@_) } };
105 my $rel_obj = $self->_relationships->{$rel};
106 $self->throw( "No such relationship ${rel}" ) unless $rel;
107 $attrs = { %{$rel_obj->{attrs} || {}}, %{$attrs || {}} };
110 $self->throw( "Invalid query: @_" ) if (@_ > 1 && (@_ % 2 == 1));
111 my $query = ((@_ > 1) ? {@_} : shift);
112 $s_cond = $self->_cond_resolve($query, $attrs);
114 $attrs->{_action} = 'convert';
115 my ($cond) = $self->_cond_resolve($rel_obj->{cond}, $attrs);
116 $cond = "${s_cond} AND ${cond}" if $s_cond;
117 return $rel_obj->{class}->retrieve_from_sql($cond, @{$attrs->{bind} || []},
122 my ($self, $rel, $values, $attrs) = @_;
123 $self->throw( "Can't call create_related as class method" )
125 $self->throw( "create_related needs a hash" )
126 unless (ref $values eq 'HASH');
127 my $rel_obj = $self->_relationships->{$rel};
128 $self->throw( "No such relationship ${rel}" ) unless $rel;
129 $self->throw( "Can't abstract implicit create for ${rel}, condition not a hash" )
130 unless ref $rel_obj->{cond} eq 'HASH';
131 $attrs = { %{$rel_obj->{attrs}}, %{$attrs || {}}, _action => 'convert' };
132 my %fields = %$values;
133 while (my ($k, $v) = each %{$rel_obj->{cond}}) {
134 $self->_cond_value($attrs, $k => $v);
135 $fields{$self->_cond_key($attrs, $k)} = (@{delete $attrs->{bind}})[0];
137 return $rel_obj->{class}->create(\%fields);
146 Matt S. Trout <perl-stuff@trout.me.uk>
150 You may distribute this code under the same terms as Perl itself.