1 package # hide from PAUSE
2 DBIx::Class::Relationship::BelongsTo;
4 # Documentation for these methods can be found in
5 # DBIx::Class::Relationship
11 my ($class, $rel, $f_class, $cond, $attrs) = @_;
13 # assume a foreign key contraint unless defined otherwise
14 $attrs->{is_foreign_key_constraint} = 1
15 if not exists $attrs->{is_foreign_key_constraint};
16 $attrs->{undef_on_null_fk} = 1
17 if not exists $attrs->{undef_on_null_fk};
19 # no join condition or just a column name
21 $class->ensure_class_loaded($f_class);
22 my %f_primaries = map { $_ => 1 } eval { $f_class->primary_columns };
23 $class->throw_exception(
24 "Can't infer join condition for ${rel} on ${class}; ".
25 "unable to load ${f_class}: $@"
28 my ($pri, $too_many) = keys %f_primaries;
29 $class->throw_exception(
30 "Can't infer join condition for ${rel} on ${class}; ".
31 "${f_class} has no primary keys"
32 ) unless defined $pri;
33 $class->throw_exception(
34 "Can't infer join condition for ${rel} on ${class}; ".
35 "${f_class} has multiple primary keys"
38 my $fk = defined $cond ? $cond : $rel;
39 $class->throw_exception(
40 "Can't infer join condition for ${rel} on ${class}; ".
41 "$fk is not a column of $class"
42 ) unless $class->has_column($fk);
44 my $acc_type = $class->has_column($rel) ? 'filter' : 'single';
45 $class->add_relationship($rel, $f_class,
46 { "foreign.${pri}" => "self.${fk}" },
47 { accessor => $acc_type, %{$attrs || {}} }
50 # explicit join condition
52 if (ref $cond eq 'HASH') { # ARRAY is also valid
55 if (m/\./) { # Explicit join condition
59 $cond_rel->{"foreign.$_"} = "self.".$cond->{$_};
63 my $acc_type = ((ref $cond eq 'HASH')
65 && $class->has_column($rel))
68 $class->add_relationship($rel, $f_class,
70 { accessor => $acc_type, %{$attrs || {}} }
74 $class->throw_exception(
75 'third argument for belongs_to must be undef, a column name, '.
84 Alexander Hartmaier <Alexander.Hartmaier@t-systems.at>
86 Matt S. Trout <mst@shadowcatsystems.co.uk>