package DBIx::Class::Storage::DBI::MultiColumnIn;
use strict;
use warnings;
use base 'DBIx::Class::Storage::DBI';
use mro 'c3';
=head1 NAME
DBIx::Class::Storage::DBI::MultiColumnIn - Storage component for RDBMS supporting multicolumn in clauses
=head1 DESCRIPTION
While ANSI SQL does not define a multicolumn in operator, many databases can
in fact understand WHERE (cola, colb) IN ( SELECT subcol_a, subcol_b ... )
The storage class for any such RDBMS should inherit from this class, in order
to dramatically speed up update/delete operations on joined multipk resultsets.
At this point the only overridden method is C<_multipk_update_delete()>
=cut
sub _multipk_update_delete {
my $self = shift;
my ($rs, $op, $values) = @_;
my $rsrc = $rs->result_source;
my @pcols = $rsrc->_pri_cols;
my $attrs = $rs->_resolved_attrs;
# naive check - this is an internal method after all, we should know what we are doing
$self->throw_exception ('Number of columns selected by supplied resultset does not match number of primary keys')
if ( ref $attrs->{select} ne 'ARRAY' or @{$attrs->{select}} != @pcols );
# This is hideously ugly, but SQLA does not understand multicol IN expressions
my $sqla = $self->_sql_maker;
my ($sql, @bind) = @${$rs->as_query};
$sql = sprintf ('(%s) IN %s', # the as_query stuff is already enclosed in ()s
join (', ', map { $sqla->_quote ($_) } @pcols),
$sql,
);
return $self->$op (
$rsrc,
$op eq 'update' ? $values : (),
\[$sql, @bind],
);
}
=head1 AUTHORS
See L<DBIx::Class/CONTRIBUTORS>
=head1 LICENSE
You may distribute this code under the same terms as Perl itself.
=cut
1;