__PACKAGE__->add_relationship('relname', 'Foreign::Class', $cond, $attrs);
+=head3 condition
+
The condition needs to be an L<SQL::Abstract>-style representation of the
join between the tables. When resolving the condition for use in a C<JOIN>,
keys using the pseudo-table C<foreign> are resolved to mean "the Table on the
To add an C<OR>ed condition, use an arrayref of hashrefs. See the
L<SQL::Abstract> documentation for more details.
-In addition to the
-L<standard ResultSet attributes|DBIx::Class::ResultSet/ATTRIBUTES>,
-the following attributes are also valid:
+=head3 attributes
+
+The L<standard ResultSet attributes|DBIx::Class::ResultSet/ATTRIBUTES> may
+be used as relationship attributes. In particular, the 'where' attribute is
+useful for filtering relationships:
+
+ __PACKAGE__->has_many( 'valid_users', 'MyApp::Schema::User',
+ { 'foreign.user_id' => 'self.user_id' },
+ { where => { valid => 1 } }
+ );
+
+The following attributes are also valid:
=over 4
An arrayref containing a list of accessors in the foreign class to create in
the main class. If, for example, you do the following:
-
+
MyDB::Schema::CD->might_have(liner_notes => 'MyDB::Schema::LinerNotes',
undef, {
proxy => [ qw/notes/ ],
});
-
+
Then, assuming MyDB::Schema::LinerNotes has an accessor named notes, you can do:
my $cd = MyDB::Schema::CD->find(1);
$cd->notes('Notes go here'); # set notes -- LinerNotes object is
# created if it doesn't exist
-
+
=item accessor
Specifies the type of accessor that should be created for the relationship.
should, set this attribute to a true or false value to override the detection
of when to create constraints.
+=item cascade_copy
+
+If C<cascade_copy> is true on a C<has_many> relationship for an
+object, then when you copy the object all the related objects will
+be copied too. To turn this behaviour off, pass C<< cascade_copy => 0 >>
+in the C<$attr> hashref.
+
+The behaviour defaults to C<< cascade_copy => 1 >> for C<has_many>
+relationships.
+
+=item cascade_delete
+
+By default, DBIx::Class cascades deletes across C<has_many>,
+C<has_one> and C<might_have> relationships. You can disable this
+behaviour on a per-relationship basis by supplying
+C<< cascade_delete => 0 >> in the relationship attributes.
+
+The cascaded operations are performed after the requested delete,
+so if your database has a constraint on the relationship, it will
+have deleted/updated the related records or raised an exception
+before DBIx::Class gets to perform the cascaded operation.
+
+=item cascade_update
+
+By default, DBIx::Class cascades updates across C<has_one> and
+C<might_have> relationships. You can disable this behaviour on a
+per-relationship basis by supplying C<< cascade_update => 0 >> in
+the relationship attributes.
+
+This is not a RDMS style cascade update - it purely means that when
+an object has update called on it, all the related objects also
+have update called. It will not change foreign keys automatically -
+you must arrange to do this yourself.
+
=item on_delete / on_update
If you are using L<SQL::Translator> to create SQL for you, you can use these
$self->throw_exception("Can't call *_related as class methods")
unless ref $self;
my $rel = shift;
- my $rel_obj = $self->relationship_info($rel);
+ my $rel_info = $self->relationship_info($rel);
$self->throw_exception( "No such relationship ${rel}" )
- unless $rel_obj;
-
+ unless $rel_info;
+
return $self->{related_resultsets}{$rel} ||= do {
my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
- $attrs = { %{$rel_obj->{attrs} || {}}, %$attrs };
+ $attrs = { %{$rel_info->{attrs} || {}}, %$attrs };
$self->throw_exception( "Invalid query: @_" )
if (@_ > 1 && (@_ % 2 == 1));
my $query = ((@_ > 1) ? {@_} : shift);
my $source = $self->result_source;
- my $cond = $source->_resolve_condition(
- $rel_obj->{cond}, $rel, $self
- );
+
+ # condition resolution may fail if an incomplete master-object prefetch
+ # is encountered - that is ok during prefetch construction (not yet in_storage)
+ my $cond = eval { $source->_resolve_condition( $rel_info->{cond}, $rel, $self ) };
+ if (my $err = $@) {
+ if ($self->in_storage) {
+ $self->throw_exception ($err);
+ }
+ else {
+ $cond = $DBIx::Class::ResultSource::UNRESOLVABLE_CONDITION;
+ }
+ }
+
if ($cond eq $DBIx::Class::ResultSource::UNRESOLVABLE_CONDITION) {
my $reverse = $source->reverse_relationship_info($rel);
foreach my $rev_rel (keys %$reverse) {
- if ($reverse->{$rev_rel}{attrs}{accessor} eq 'multi') {
+ if ($reverse->{$rev_rel}{attrs}{accessor} && $reverse->{$rev_rel}{attrs}{accessor} eq 'multi') {
$attrs->{related_objects}{$rev_rel} = [ $self ];
Scalar::Util::weaken($attrs->{related_object}{$rev_rel}[0]);
} else {
( $objects_rs ) = $rs->search_related_rs('relname', $cond, $attrs);
This method works exactly the same as search_related, except that
-it guarantees a restultset, even in list context.
+it guarantees a resultset, even in list context.
=cut
call set_from_related on the book.
This is called internally when you pass existing objects as values to
-L<DBIx::Class::ResultSet/create>, or pass an object to a belongs_to acessor.
+L<DBIx::Class::ResultSet/create>, or pass an object to a belongs_to accessor.
The columns are only set in the local copy of the object, call L</update> to
set them in the storage.
sub set_from_related {
my ($self, $rel, $f_obj) = @_;
- my $rel_obj = $self->relationship_info($rel);
- $self->throw_exception( "No such relationship ${rel}" ) unless $rel_obj;
- my $cond = $rel_obj->{cond};
+ my $rel_info = $self->relationship_info($rel);
+ $self->throw_exception( "No such relationship ${rel}" ) unless $rel_info;
+ my $cond = $rel_info->{cond};
$self->throw_exception(
"set_from_related can only handle a hash condition; the ".
"condition for $rel is of type ".
(ref $cond ? ref $cond : 'plain scalar')
) unless ref $cond eq 'HASH';
if (defined $f_obj) {
- my $f_class = $rel_obj->{class};
+ my $f_class = $rel_info->{class};
$self->throw_exception( "Object $f_obj isn't a ".$f_class )
unless Scalar::Util::blessed($f_obj) and $f_obj->isa($f_class);
}
$self->set_columns(
$self->result_source->_resolve_condition(
- $rel_obj->{cond}, $f_obj, $rel));
+ $rel_info->{cond}, $f_obj, $rel));
return 1;
}
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