package DBIx::Class::ResultSetColumn;
+
use strict;
use warnings;
+
use base 'DBIx::Class';
+
+use Carp::Clan qw/^DBIx::Class/;
+use DBIx::Class::Exception;
use List::Util;
=head1 NAME
my $select = defined $as_index ? $select_list->[$as_index] : $column;
# {collapse} would mean a has_many join was injected, which in turn means
- # we need to group IF WE CAN (only if the column in question is unique)
+ # we need to group *IF WE CAN* (only if the column in question is unique)
if (!$new_attrs->{group_by} && keys %{$orig_attrs->{collapse}}) {
# scan for a constraint that would contain our column only - that'd be proof
if ($col eq $select or $fqcol eq $select) {
$new_attrs->{group_by} = [ $select ];
+ delete $new_attrs->{distinct}; # it is ignored when group_by is present
last;
}
}
+
+ if (!$new_attrs->{group_by}) {
+ carp (
+ "Attempting to retrieve non-unique column '$column' on a resultset containing "
+ . 'one-to-many joins will return duplicate results.'
+ );
+ }
}
my $new = bless { _select => $select, _as => $column, _parent_resultset => $new_parent_rs }, $class;
sub next {
my $self = shift;
+
+ # using cursor so we don't inflate anything
my ($row) = $self->_resultset->cursor->next;
+
return $row;
}
sub all {
my $self = shift;
+
+ # using cursor so we don't inflate anything
return map { $_->[0] } $self->_resultset->cursor->all;
}
sub first {
my $self = shift;
- my ($row) = $self->_resultset->cursor->reset->next;
+
+ # using cursor so we don't inflate anything
+ $self->_resultset->cursor->reset;
+ my ($row) = $self->_resultset->cursor->next;
+
+ return $row;
+}
+
+=head2 single
+
+=over 4
+
+=item Arguments: none
+
+=item Return Value: $value
+
+=back
+
+Much like L<DBIx::Class::ResultSet/single> fetches one and only one column
+value using the cursor directly. If additional rows are present a warning
+is issued before discarding the cursor.
+
+=cut
+
+sub single {
+ my $self = shift;
+
+ my $attrs = $self->_resultset->_resolved_attrs;
+ my ($row) = $self->_resultset->result_source->storage->select_single(
+ $attrs->{from}, $attrs->{select}, $attrs->{where}, $attrs
+ );
+
return $row;
}
sub func {
my ($self,$function) = @_;
my $cursor = $self->func_rs($function)->cursor;
-
+
if( wantarray ) {
return map { $_->[ 0 ] } $cursor->all;
}
=head2 throw_exception
See L<DBIx::Class::Schema/throw_exception> for details.
-
+
=cut
-
+
sub throw_exception {
my $self=shift;
+
if (ref $self && $self->{_parent_resultset}) {
- $self->{_parent_resultset}->throw_exception(@_)
- } else {
- croak(@_);
+ $self->{_parent_resultset}->throw_exception(@_);
+ }
+ else {
+ DBIx::Class::Exception->throw(@_);
}
}
#
# Returns the underlying resultset. Creates it from the parent resultset if
# necessary.
-#
+#
sub _resultset {
my $self = shift;