X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?a=blobdiff_plain;f=lib%2FDBIx%2FClass%2FResultSetColumn.pm;h=1efdc35eef7ac94210a5957010011575afb44c71;hb=HEAD;hp=5a5f26de32262512b3ec48420a40f1325be53522;hpb=3484603a5f50f61c22a426cdb3b2abc551716ad6;p=dbsrgits%2FDBIx-Class.git diff --git a/lib/DBIx/Class/ResultSetColumn.pm b/lib/DBIx/Class/ResultSetColumn.pm index 5a5f26d..1efdc35 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 'fail_on_internal_call'; +use namespace::clean; =head1 NAME @@ -36,18 +40,98 @@ 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 - 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 @@ -61,15 +145,16 @@ sub new { 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 $self = shift; - my ($row) = $self->_resultset->cursor->next; - return $row; + #my $self = shift; + + # using cursor so we don't inflate anything + ($_[0]->_resultset->cursor->next)[0]; } =head2 all @@ -86,13 +171,15 @@ 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; - return map { $_->[0] } $self->_resultset->cursor->all; + #my $self = shift; + + # using cursor so we don't inflate anything + map { $_->[0] } $_[0]->_resultset->cursor->all; } =head2 reset @@ -113,9 +200,10 @@ Much like L. =cut sub reset { - my $self = shift; - $self->_resultset->cursor->reset; - return $self; + #my $self = shift; + + $_[0]->_resultset->reset; + $_[0]; } =head2 first @@ -135,10 +223,40 @@ Much like L but just returning the one value. =cut -sub first { - my $self = shift; - my ($row) = $self->_resultset->cursor->reset->next; - return $row; +sub first :DBIC_method_is_indirect_sugar { + DBIx::Class::_ENV_::ASSERT_NO_INTERNAL_INDIRECT_CALLS and fail_on_internal_call; + + # using cursor so we don't inflate anything + my $cursor = $_[0]->_resultset->cursor; + $cursor->reset; + ($cursor->next)[0]; +} + +=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 $rs = $_[0]->_resultset; + + my $attrs = $rs->_resolved_attrs; + ($rs->result_source->schema->storage->select_single( + $attrs->{from}, $attrs->{select}, $attrs->{where}, $attrs + ))[0]; } =head2 min @@ -158,8 +276,30 @@ 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; + $_[0]->func('MIN'); +} + +=head2 min_rs + +=over 4 + +=item Arguments: none + +=item Return Value: L<$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 @@ -179,8 +319,30 @@ 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; + $_[0]->func('MAX'); +} + +=head2 max_rs + +=over 4 + +=item Arguments: none + +=item Return Value: L<$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 @@ -200,8 +362,30 @@ 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; + $_[0]->func('SUM'); +} + +=head2 sum_rs + +=over 4 + +=item Arguments: none + +=item Return Value: L<$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; + $_[0]->func_rs('SUM') } =head2 func @@ -224,71 +408,130 @@ value. Produces the following SQL: =cut -sub func { - my ($self,$function) = @_; - my $cursor = $self->{_parent_resultset}->search(undef, {select => {$function => $self->{_select}}, as => [$self->{_as}]})->cursor; - - if( wantarray ) { - return map { $_->[ 0 ] } $cursor->all; - } +sub func :DBIC_method_is_indirect_sugar{ + DBIx::Class::_ENV_::ASSERT_NO_INTERNAL_INDIRECT_CALLS and fail_on_internal_call; - return ( $cursor->next )[ 0 ]; -} - -=head2 throw_exception + #my ($self,$function) = @_; + my $cursor = $_[0]->func_rs($_[1])->cursor; -See L for details. - -=cut - -sub throw_exception { - my $self=shift; - if (ref $self && $self->{_parent_resultset}) { - $self->{_parent_resultset}->throw_exception(@_) - } else { - croak(@_); - } + wantarray + ? map { $_->[ 0 ] } $cursor->all + : ( $cursor->next )[ 0 ] + ; } -=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 - $year_col->_resultset->next +Creates the resultset that C uses to run its query. + +=cut + +sub func_rs { + my ($self,$function) = @_; -Returns the underlying resultset. Creates it from the parent resultset if -necessary. + 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' + ); + + $rs->search_rs( undef, { + columns => { $self->{_as} => { $function => $select } } + } ); +} + +=head2 throw_exception + +See L 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 = $self->{_select}; -Luke Saunders + if ($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_rs(undef, { + columns => { $self->{_as} => $select } + }); + }; +} + +=head1 FURTHER QUESTIONS? + +Check the list of L. + +=head1 COPYRIGHT AND LICENSE + +This module is free software L +by the L. You can +redistribute it and/or modify it under the same terms as the +L. =cut + +1; +