package DBIx::Class::ResultSetColumn;
+
use strict;
use warnings;
+
use base 'DBIx::Class';
-use List::Util;
+use DBIx::Class::Carp;
+use DBIx::Class::_Util qw( fail_on_internal_wantarray fail_on_internal_call );
+use namespace::clean;
=head1 NAME
sub new {
my ($class, $rs, $column) = @_;
$class = ref $class if ref $class;
- my $new_parent_rs = $rs->search_rs; # we don't want to mess up the original, so clone it
- my $attrs = $new_parent_rs->_resolved_attrs;
- $new_parent_rs->{attrs}->{$_} = undef for qw(prefetch include_columns +select +as); # prefetch, include_columns, +select, +as cause additional columns to be fetched
- my ($select, $as) =
- map { defined $_ ? ($attrs->{select}->[$_], $attrs->{as}->[$_]) : ($column, $column) }
- List::Util::first { ($attrs->{as} || [])->[$_] eq $column }
- 0..$#{$attrs->{as} || []};
- my $new = bless { _select => $select, _as => $as, _parent_resultset => $new_parent_rs }, $class;
- $new->throw_exception("column must be supplied") unless $column;
- return $new;
+
+ $rs->throw_exception('column must be supplied') unless $column;
+
+ my $orig_attrs = $rs->_resolved_attrs;
+ my $alias = $rs->current_source_alias;
+ my $rsrc = $rs->result_source;
+
+ # If $column can be found in the 'as' list of the parent resultset, use the
+ # corresponding element of its 'select' list (to keep any custom column
+ # definition set up with 'select' or '+select' attrs), otherwise use $column
+ # (to create a new column definition on-the-fly).
+ my $as_list = $orig_attrs->{as} || [];
+ my $select_list = $orig_attrs->{select} || [];
+ my ($as_index) = grep { ($as_list->[$_] || "") eq $column } 0..$#$as_list;
+ my $select = defined $as_index ? $select_list->[$as_index] : $column;
+
+ my $colmap;
+ for ($rsrc->columns, $column) {
+ if ($_ =~ /^ \Q$alias\E \. ([^\.]+) $ /x) {
+ $colmap->{$_} = $1;
+ }
+ elsif ($_ !~ /\./) {
+ $colmap->{"$alias.$_"} = $_;
+ $colmap->{$_} = $_;
+ }
+ }
+
+ my $new_parent_rs;
+ # analyze the order_by, and see if it is done over a function/nonexistentcolumn
+ # if this is the case we will need to wrap a subquery since the result of RSC
+ # *must* be a single column select
+ if (
+ scalar grep
+ { ! exists $colmap->{$_->[0]} }
+ ( $rsrc->schema->storage->_extract_order_criteria ($orig_attrs->{order_by} ) )
+ ) {
+ # nuke the prefetch before collapsing to sql
+ my $subq_rs = $rs->search_rs;
+ $subq_rs->{attrs}{join} = $subq_rs->_merge_joinpref_attr( $subq_rs->{attrs}{join}, delete $subq_rs->{attrs}{prefetch} );
+ $new_parent_rs = $subq_rs->as_subselect_rs;
+ }
+
+ $new_parent_rs ||= $rs->search_rs;
+ my $new_attrs = $new_parent_rs->{attrs} ||= {};
+
+ # prefetch causes additional columns to be fetched, but we can not just make a new
+ # rs via the _resolved_attrs trick - we need to retain the separation between
+ # +select/+as and select/as. At the same time we want to preserve any joins that the
+ # prefetch would otherwise generate.
+ $new_attrs->{join} = $rs->_merge_joinpref_attr( $new_attrs->{join}, delete $new_attrs->{prefetch} );
+
+ # {collapse} would mean a has_many join was injected, which in turn means
+ # we need to group *IF WE CAN* (only if the column in question is unique)
+ if (!$orig_attrs->{group_by} && $orig_attrs->{collapse}) {
+
+ if ($colmap->{$select} and $rsrc->_identifying_column_set([$colmap->{$select}])) {
+ $new_attrs->{group_by} = [ $select ];
+ delete @{$new_attrs}{qw(distinct _grouped_by_distinct)}; # it is ignored when group_by is present
+ }
+ else {
+ carp (
+ "Attempting to retrieve non-unique column '$column' on a resultset containing "
+ . 'one-to-many joins will return duplicate results.'
+ );
+ }
+ }
+
+ return bless {
+ _select => $select,
+ _as => $column,
+ _parent_resultset => $new_parent_rs
+ }, $class;
}
+=head2 as_query
+
+=over 4
+
+=item Arguments: none
+
+=item Return Value: \[ $sql, L<@bind_values|DBIx::Class::ResultSet/DBIC BIND VALUES> ]
+
+=back
+
+Returns the SQL query and bind vars associated with the invocant.
+
+This is generally used as the RHS for a subquery.
+
+=cut
+
+sub as_query { return shift->_resultset->as_query(@_) }
+
=head2 next
=over 4
Returns the next value of the column in the resultset (or C<undef> if
there is none).
-Much like L<DBIx::Class::ResultSet/next> but just returning the
+Much like L<DBIx::Class::ResultSet/next> but just returning the
one value.
=cut
sub next {
my $self = shift;
+
+ # using cursor so we don't inflate anything
my ($row) = $self->_resultset->cursor->next;
+
return $row;
}
there are none).
Much like L<DBIx::Class::ResultSet/all> but returns values rather
-than row objects.
+than result objects.
=cut
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->schema->storage->select_single(
+ $attrs->{from}, $attrs->{select}, $attrs->{where}, $attrs
+ );
+
return $row;
}
=cut
-sub min {
- return shift->func('MIN');
+sub min :DBIC_method_is_indirect_sugar {
+ DBIx::Class::_ENV_::ASSERT_NO_INTERNAL_INDIRECT_CALLS and fail_on_internal_call;
+ $_[0]->func('MIN');
+}
+
+=head2 min_rs
+
+=over 4
+
+=item Arguments: none
+
+=item Return Value: L<$resultset|DBIx::Class::ResultSet>
+
+=back
+
+ my $rs = $year_col->min_rs();
+
+Wrapper for ->func_rs for function MIN().
+
+=cut
+
+sub min_rs :DBIC_method_is_indirect_sugar {
+ DBIx::Class::_ENV_::ASSERT_NO_INTERNAL_INDIRECT_CALLS and fail_on_internal_call;
+ $_[0]->func_rs('MIN')
}
=head2 max
=cut
-sub max {
- return shift->func('MAX');
+sub max :DBIC_method_is_indirect_sugar {
+ DBIx::Class::_ENV_::ASSERT_NO_INTERNAL_INDIRECT_CALLS and fail_on_internal_call;
+ $_[0]->func('MAX');
+}
+
+=head2 max_rs
+
+=over 4
+
+=item Arguments: none
+
+=item Return Value: L<$resultset|DBIx::Class::ResultSet>
+
+=back
+
+ my $rs = $year_col->max_rs();
+
+Wrapper for ->func_rs for function MAX().
+
+=cut
+
+sub max_rs :DBIC_method_is_indirect_sugar {
+ DBIx::Class::_ENV_::ASSERT_NO_INTERNAL_INDIRECT_CALLS and fail_on_internal_call;
+ $_[0]->func_rs('MAX')
}
=head2 sum
=cut
-sub sum {
- return shift->func('SUM');
+sub sum :DBIC_method_is_indirect_sugar {
+ DBIx::Class::_ENV_::ASSERT_NO_INTERNAL_INDIRECT_CALLS and fail_on_internal_call;
+ $_[0]->func('SUM');
+}
+
+=head2 sum_rs
+
+=over 4
+
+=item Arguments: none
+
+=item Return Value: L<$resultset|DBIx::Class::ResultSet>
+
+=back
+
+ my $rs = $year_col->sum_rs();
+
+Wrapper for ->func_rs for function SUM().
+
+=cut
+
+sub sum_rs :DBIC_method_is_indirect_sugar {
+ DBIx::Class::_ENV_::ASSERT_NO_INTERNAL_INDIRECT_CALLS and fail_on_internal_call;
+ $_[0]->func_rs('SUM')
}
=head2 func
sub func {
my ($self,$function) = @_;
- my $cursor = $self->{_parent_resultset}->search(undef, {select => {$function => $self->{_select}}, as => [$self->{_as}]})->cursor;
-
+ my $cursor = $self->func_rs($function)->cursor;
+
if( wantarray ) {
+ DBIx::Class::_ENV_::ASSERT_NO_INTERNAL_WANTARRAY and my $sog = fail_on_internal_wantarray;
return map { $_->[ 0 ] } $cursor->all;
}
return ( $cursor->next )[ 0 ];
}
-=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(@_);
- }
-}
-
-=head2 _resultset
+=head2 func_rs
=over 4
-=item Arguments: none
+=item Arguments: $function
-=item Return Value: $resultset
+=item Return Value: L<$resultset|DBIx::Class::ResultSet>
=back
- $year_col->_resultset->next
+Creates the resultset that C<func()> uses to run its query.
+
+=cut
-Returns the underlying resultset. Creates it from the parent resultset if
-necessary.
+sub func_rs {
+ my ($self,$function) = @_;
+
+ my $rs = $self->{_parent_resultset};
+ my $select = $self->{_select};
+
+ # wrap a grouped rs
+ if ($rs->_resolved_attrs->{group_by}) {
+ $select = $self->{_as};
+ $rs = $rs->as_subselect_rs;
+ }
+
+ # FIXME - remove at some point in the future (2018-ish)
+ wantarray
+ and
+ carp_unique(
+ 'Starting with DBIC@0.082900 func_rs() always returns a ResultSet '
+ . 'instance regardless of calling context. Please force scalar() context to '
+ . 'silence this warning'
+ )
+ and
+ DBIx::Class::_ENV_::ASSERT_NO_INTERNAL_WANTARRAY
+ and
+ my $sog = fail_on_internal_wantarray
+ ;
+
+ $rs->search_rs( undef, {
+ columns => { $self->{_as} => { $function => $select } }
+ } );
+}
+
+=head2 throw_exception
+
+See L<DBIx::Class::Schema/throw_exception> for details.
=cut
-sub _resultset {
+sub throw_exception {
my $self = shift;
- return $self->{_resultset} ||= $self->{_parent_resultset}->search(undef,
- {
- select => [$self->{_select}],
- as => [$self->{_as}]
- }
- );
+ if (ref $self && $self->{_parent_resultset}) {
+ $self->{_parent_resultset}->throw_exception(@_);
+ }
+ else {
+ DBIx::Class::Exception->throw(@_);
+ }
}
+# _resultset
+#
+# Arguments: none
+#
+# Return Value: $resultset
+#
+# $year_col->_resultset->next
+#
+# Returns the underlying resultset. Creates it from the parent resultset if
+# necessary.
+#
+sub _resultset {
+ my $self = shift;
-1;
+ return $self->{_resultset} ||= do {
-=head1 AUTHORS
+ my $select = $self->{_select};
-Luke Saunders <luke.saunders@gmail.com>
+ if ($self->{_parent_resultset}{attrs}{distinct}) {
+ my $alias = $self->{_parent_resultset}->current_source_alias;
+ my $rsrc = $self->{_parent_resultset}->result_source;
+ my %cols = map { $_ => 1, "$alias.$_" => 1 } $rsrc->columns;
-Jess Robinson
+ unless( $cols{$select} ) {
+ carp_unique(
+ 'Use of distinct => 1 while selecting anything other than a column '
+ . 'declared on the primary ResultSource is deprecated (you selected '
+ . "'$self->{_as}') - please supply an explicit group_by instead"
+ );
-=head1 LICENSE
+ # collapse the selector to a literal so that it survives the distinct parse
+ # if it turns out to be an aggregate - at least the user will get a proper exception
+ # instead of silent drop of the group_by altogether
+ $select = \[ $rsrc->schema->storage->sql_maker->_recurse_fields($select) ];
+ }
+ }
-You may distribute this code under the same terms as Perl itself.
+ $self->{_parent_resultset}->search(undef, {
+ columns => { $self->{_as} => $select }
+ });
+ };
+}
+
+=head1 FURTHER QUESTIONS?
+
+Check the list of L<additional DBIC resources|DBIx::Class/GETTING HELP/SUPPORT>.
+
+=head1 COPYRIGHT AND LICENSE
+
+This module is free software L<copyright|DBIx::Class/COPYRIGHT AND LICENSE>
+by the L<DBIx::Class (DBIC) authors|DBIx::Class/AUTHORS>. You can
+redistribute it and/or modify it under the same terms as the
+L<DBIx::Class library|DBIx::Class/COPYRIGHT AND LICENSE>.
=cut
+
+1;
+
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