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=1596e53b84720f8ec24952f0e38da83297dcd2df;hpb=d8dbe471a2f98a0bc2de5e629f22ee2f2ec034ef;p=dbsrgits%2FDBIx-Class.git diff --git a/lib/DBIx/Class/ResultSetColumn.pm b/lib/DBIx/Class/ResultSetColumn.pm index 1596e53..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 @@ -37,61 +41,86 @@ sub new { my ($class, $rs, $column) = @_; $class = ref $class if ref $class; - $rs->throw_exception("column must be supplied") unless $column; + $rs->throw_exception('column must be supplied') unless $column; my $orig_attrs = $rs->_resolved_attrs; - my $new_parent_rs = $rs->search_rs; - - # 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. - - my $new_attrs = $new_parent_rs->{attrs} ||= {}; - $new_attrs->{join} = $rs->_merge_attr( delete $new_attrs->{join}, delete $new_attrs->{prefetch} ); + 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 $as_index = List::Util::first { ($as_list->[$_] || "") eq $column } 0..$#$as_list; + my ($as_index) = grep { ($as_list->[$_] || "") eq $column } 0..$#$as_list; my $select = defined $as_index ? $select_list->[$as_index] : $column; - # {collapse} would mean a has_many join was injected, which in turn means - # we need to group IF WE CAN (only if the column in question is unique) - if (!$new_attrs->{group_by} && keys %{$orig_attrs->{collapse}}) { + my $colmap; + for ($rsrc->columns, $column) { + if ($_ =~ /^ \Q$alias\E \. ([^\.]+) $ /x) { + $colmap->{$_} = $1; + } + elsif ($_ !~ /\./) { + $colmap->{"$alias.$_"} = $_; + $colmap->{$_} = $_; + } + } - # scan for a constraint that would contain our column only - that'd be proof - # enough it is unique - my $constraints = { $rs->result_source->unique_constraints }; - for my $constraint_columns ( values %$constraints ) { + 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 = $subq_rs->as_subselect_rs; + } - next unless @$constraint_columns == 1; + $new_parent_rs ||= $rs->search_rs; + my $new_attrs = $new_parent_rs->{attrs} ||= {}; - my $col = $constraint_columns->[0]; - my $fqcol = join ('.', $new_attrs->{alias}, $col); + # 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 $new_attrs->{prefetch} ); - if ($col eq $select or $fqcol eq $select) { - $new_attrs->{group_by} = [ $select ]; - last; - } + # {collapse} would mean a has_many join was injected, which in turn means + # we need to group *IF WE CAN* (only if the column in question is unique) + if (!$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.' + ); } } - my $new = bless { _select => $select, _as => $column, _parent_resultset => $new_parent_rs }, $class; - return $new; + return bless { + _select => $select, + _as => $column, + _parent_resultset => $new_parent_rs + }, $class; } -=head2 as_query (EXPERIMENTAL) +=head2 as_query =over 4 =item Arguments: none -=item Return Value: \[ $sql, @bind ] +=item Return Value: \[ $sql, L<@bind_values|DBIx::Class::ResultSet/DBIC BIND VALUES> ] =back @@ -99,8 +128,6 @@ Returns the SQL query and bind vars associated with the invocant. This is generally used as the RHS for a subquery. -B: This feature is still experimental. - =cut sub as_query { return shift->_resultset->as_query(@_) } @@ -118,15 +145,16 @@ 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 $self = shift; - my ($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 @@ -143,13 +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 @@ -170,9 +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 @@ -192,10 +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 @@ -215,8 +276,9 @@ 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 @@ -225,7 +287,7 @@ sub min { =item Arguments: none -=item Return Value: $resultset +=item Return Value: L<$resultset|DBIx::Class::ResultSet> =back @@ -235,7 +297,10 @@ 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 @@ -254,8 +319,9 @@ 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 @@ -264,7 +330,7 @@ sub max { =item Arguments: none -=item Return Value: $resultset +=item Return Value: L<$resultset|DBIx::Class::ResultSet> =back @@ -274,7 +340,10 @@ 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 @@ -293,8 +362,9 @@ 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 @@ -303,7 +373,7 @@ sub sum { =item Arguments: none -=item Return Value: $resultset +=item Return Value: L<$resultset|DBIx::Class::ResultSet> =back @@ -313,7 +383,10 @@ 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; + $_[0]->func_rs('SUM') +} =head2 func @@ -335,15 +408,16 @@ value. Produces the following SQL: =cut -sub func { - my ($self,$function) = @_; - my $cursor = $self->func_rs($function)->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 ( $cursor->next )[ 0 ]; + #my ($self,$function) = @_; + my $cursor = $_[0]->func_rs($_[1])->cursor; + + wantarray + ? map { $_->[ 0 ] } $cursor->all + : ( $cursor->next )[ 0 ] + ; } =head2 func_rs @@ -352,7 +426,7 @@ sub func { =item Arguments: $function -=item Return Value: $resultset +=item Return Value: L<$resultset|DBIx::Class::ResultSet> =back @@ -362,26 +436,44 @@ 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' ); + + $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(@_); } } @@ -395,28 +487,51 @@ 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_rs(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