X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?a=blobdiff_plain;f=lib%2FDBIx%2FClass%2FResultSetColumn.pm;h=5b510de45685b3ae52492cad78562f37ec1675ad;hb=6c5aa1fbffdc9e5679d2f68780b11a9569ec1993;hp=3248ecba092f814a3f8db37a56983d035ef18ef2;hpb=4fa7bc220537c54f6cb7ca6d2ff7b3c0f68e1233;p=dbsrgits%2FDBIx-Class.git diff --git a/lib/DBIx/Class/ResultSetColumn.pm b/lib/DBIx/Class/ResultSetColumn.pm index 3248ecb..5b510de 100644 --- a/lib/DBIx/Class/ResultSetColumn.pm +++ b/lib/DBIx/Class/ResultSetColumn.pm @@ -1,8 +1,12 @@ 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 @@ -36,22 +40,78 @@ passed as params. Used internally by L. 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 + + $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 = $attrs->{as} || []; - my $select_list = $attrs->{select} || []; - my $as_index = List::Util::first { ($as_list->[$_] || "") eq $column } 0..$#$as_list; + 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 $new = bless { _select => $select, _as => $column, _parent_resultset => $new_parent_rs }, $class; - $new->throw_exception("column must be supplied") unless $column; - return $new; + 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 @@ -60,7 +120,7 @@ sub new { =item Arguments: none -=item Return Value: \[ $sql, @bind ] +=item Return Value: \[ $sql, L<@bind_values|DBIx::Class::ResultSet/DBIC BIND VALUES> ] =back @@ -70,7 +130,7 @@ This is generally used as the RHS for a subquery. =cut -sub as_query { return shift->_resultset->as_query } +sub as_query { return shift->_resultset->as_query(@_) } =head2 next @@ -85,14 +145,17 @@ sub as_query { return shift->_resultset->as_query } Returns the next value of the column in the resultset (or C if there is none). -Much like L but just returning the +Much like L 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; } @@ -110,12 +173,14 @@ Returns all values of the column in the resultset (or C if there are none). Much like L 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; } @@ -161,7 +226,38 @@ Much like L but just returning the one value. 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 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; } @@ -182,8 +278,9 @@ resultset (or C if there are none). =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 @@ -192,7 +289,7 @@ sub min { =item Arguments: none -=item Return Value: $resultset +=item Return Value: L<$resultset|DBIx::Class::ResultSet> =back @@ -202,7 +299,10 @@ Wrapper for ->func_rs for function MIN(). =cut -sub min_rs { return shift->func_rs('MIN') } +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 @@ -221,8 +321,9 @@ resultset (or C if there are none). =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 @@ -231,7 +332,7 @@ sub max { =item Arguments: none -=item Return Value: $resultset +=item Return Value: L<$resultset|DBIx::Class::ResultSet> =back @@ -241,7 +342,10 @@ Wrapper for ->func_rs for function MAX(). =cut -sub max_rs { return shift->func_rs('MAX') } +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 @@ -260,8 +364,9 @@ the resultset. Use on varchar-like columns at your own risk. =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 @@ -270,7 +375,7 @@ sub sum { =item Arguments: none -=item Return Value: $resultset +=item Return Value: L<$resultset|DBIx::Class::ResultSet> =back @@ -280,7 +385,10 @@ Wrapper for ->func_rs for function SUM(). =cut -sub sum_rs { return shift->func_rs('SUM') } +sub sum_rs :DBIC_method_is_indirect_sugar { + DBIx::Class::_ENV_::ASSERT_NO_INTERNAL_INDIRECT_CALLS and fail_on_internal_call; + $_[0]->func_rs('SUM') +} =head2 func @@ -305,8 +413,9 @@ value. Produces the following SQL: sub func { my ($self,$function) = @_; 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; } @@ -319,7 +428,7 @@ sub func { =item Arguments: $function -=item Return Value: $resultset +=item Return Value: L<$resultset|DBIx::Class::ResultSet> =back @@ -329,26 +438,49 @@ Creates the resultset that C uses to run its query. sub func_rs { my ($self,$function) = @_; - return $self->{_parent_resultset}->search( - undef, { - select => {$function => $self->{_select}}, - as => [$self->{_as}], - }, - ); + + 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 for details. - -=cut - + +=cut + sub throw_exception { - my $self=shift; + 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(@_); } } @@ -362,28 +494,51 @@ sub throw_exception { # # Returns the underlying resultset. Creates it from the parent resultset if # necessary. -# +# sub _resultset { my $self = shift; - return $self->{_resultset} ||= $self->{_parent_resultset}->search(undef, - { - select => [$self->{_select}], - as => [$self->{_as}] + return $self->{_resultset} ||= do { + + my $select = $self->{_select}; + + if ($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; + + 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" + ); + + # 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) ]; + } } - ); + + $self->{_parent_resultset}->search(undef, { + columns => { $self->{_as} => $select } + }); + }; } -1; +=head1 FURTHER QUESTIONS? -=head1 AUTHORS +Check the list of L. -Luke Saunders +=head1 COPYRIGHT AND LICENSE -Jess Robinson +This module is free software L +by the L. You can +redistribute it and/or modify it under the same terms as the +L. -=head1 LICENSE +=cut -You may distribute this code under the same terms as Perl itself. +1; -=cut