[dbsrgits/DBIx-Class.git] / lib / DBIx / Class / Storage / DBI / AmbiguousGlob.pm

package DBIx::Class::Storage::DBI::AmbiguousGlob;

use strict;
use warnings;

use base 'DBIx::Class::Storage::DBI';

=head1 NAME

DBIx::Class::Storage::DBI::AmbiguousGlob - Storage component for RDBMS supporting multicolumn in clauses

=head1 DESCRIPTION

Some servers choke on things like:

  COUNT(*) FROM (SELECT tab1.col, tab2.col FROM tab1 JOIN tab2 ... )

claiming that col is a duplicate column (it loses the table specifiers by
the time it gets to the *). Thus for any subquery count we select only the
primary keys of the main table in the inner query. This hopefully still
hits the indexes and keeps the server happy.

At this point the only overriden method is C<_subq_count_select()>

=cut

sub _subq_count_select {
  my ($self, $source, $rs_attrs) = @_;
  my @pcols = map { join '.', $rs_attrs->{alias}, $_ } ($source->primary_columns);
  return @pcols ? \@pcols : [ 1 ];
}

=head1 AUTHORS

See L<DBIx::Class/CONTRIBUTORS>

=head1 LICENSE

You may distribute this code under the same terms as Perl itself.

=cut

1;
Commit	Line	Data
efe2cc83	1	package DBIx::Class::Storage::DBI::AmbiguousGlob;
	2
	3	use strict;
	4	use warnings;
	5
	6	use base 'DBIx::Class::Storage::DBI';
	7
	8	=head1 NAME
	9
	10	DBIx::Class::Storage::DBI::AmbiguousGlob - Storage component for RDBMS supporting multicolumn in clauses
	11
	12	=head1 DESCRIPTION
	13
	14	Some servers choke on things like:
	15
	16	COUNT(*) FROM (SELECT tab1.col, tab2.col FROM tab1 JOIN tab2 ... )
	17
	18	claiming that col is a duplicate column (it loses the table specifiers by
	19	the time it gets to the *). Thus for any subquery count we select only the
	20	primary keys of the main table in the inner query. This hopefully still
	21	hits the indexes and keeps the server happy.
	22
618a0fe3	23	At this point the only overriden method is C<_subq_count_select()>
efe2cc83	24
	25	=cut
	26
618a0fe3	27	sub _subq_count_select {
	28	my ($self, $source, $rs_attrs) = @_;
	29	my @pcols = map { join '.', $rs_attrs->{alias}, $_ } ($source->primary_columns);
	30	return @pcols ? \@pcols : [ 1 ];
efe2cc83	31	}
	32
	33	=head1 AUTHORS
	34
	35	See L<DBIx::Class/CONTRIBUTORS>
	36
	37	=head1 LICENSE
	38
	39	You may distribute this code under the same terms as Perl itself.
	40
	41	=cut
	42
	43	1;