package DBIx::Class::PK;
use strict;
use warnings;
use base qw/DBIx::Class::Row/;
=head1 NAME
DBIx::Class::PK - Primary Key class
=head1 SYNOPSIS
=head1 DESCRIPTION
This class contains methods for handling primary keys and methods
depending on them.
=head1 METHODS
=cut
=head2 id
Returns the primary key(s) for a row. Can't be called as
a class method.
=cut
sub id {
my ($self) = @_;
$self->throw_exception( "Can't call id() as a class method" )
unless ref $self;
my @id_vals = $self->_ident_values;
return (wantarray ? @id_vals : $id_vals[0]);
}
sub _ident_values {
my ($self) = @_;
my (@ids, @missing);
for ($self->_pri_cols) {
push @ids, $self->get_column($_);
push @missing, $_ if (! defined $ids[-1] and ! $self->has_column_loaded ($_) );
}
if (@missing && $self->in_storage) {
$self->throw_exception (
'Unable to uniquely identify row object with missing PK columns: '
. join (', ', @missing )
);
}
return @ids;
}
=head2 ID
Returns a unique id string identifying a row object by primary key.
Used by L<DBIx::Class::CDBICompat::LiveObjectIndex> and
L<DBIx::Class::ObjectCache>.
=over
=item WARNING
The default C<_create_ID> method used by this function orders the returned
values by the alphabetical order of the primary column names, B<unlike>
the L</id> method, which follows the same order in which columns were fed
to L<DBIx::Class::ResultSource/set_primary_key>.
=back
=cut
sub ID {
my ($self) = @_;
$self->throw_exception( "Can't call ID() as a class method" )
unless ref $self;
return undef unless $self->in_storage;
return $self->_create_ID(%{$self->ident_condition});
}
sub _create_ID {
my ($self, %vals) = @_;
return undef unless 0 == grep { !defined } values %vals;
return join '|', ref $self || $self, $self->result_source->name,
map { $_ . '=' . $vals{$_} } sort keys %vals;
}
=head2 ident_condition
my $cond = $result_source->ident_condition();
my $cond = $result_source->ident_condition('alias');
Produces a condition hash to locate a row based on the primary key(s).
=cut
sub ident_condition {
my ($self, $alias) = @_;
my @pks = $self->_pri_cols;
my @vals = $self->_ident_values;
my (%cond, @undef);
my $prefix = defined $alias ? $alias.'.' : '';
for my $col (@pks) {
if (! defined ($cond{$prefix.$col} = shift @vals) ) {
push @undef, $col;
}
}
if (@undef && $self->in_storage) {
$self->throw_exception (
'Unable to construct row object identity condition due to NULL PK columns: '
. join (', ', @undef)
);
}
return \%cond;
}
1;
=head1 AUTHORS
Matt S. Trout <mst@shadowcatsystems.co.uk>
=head1 LICENSE
You may distribute this code under the same terms as Perl itself.
=cut