X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?a=blobdiff_plain;f=lib%2FDBIx%2FClass%2FResultSetColumn.pm;h=e26b6c2f3ab7ea2557ab1f90abb89ccb5b1f87de;hb=71b788fb0a6ec693cb27c44e326f01a219caf1a4;hp=ee1ed04b480b5a2b05056b64d91ab9817a4d744c;hpb=4e55c3ae65c1a0c1ef55043fb44bff52d1a1c5a1;p=dbsrgits%2FDBIx-Class.git diff --git a/lib/DBIx/Class/ResultSetColumn.pm b/lib/DBIx/Class/ResultSetColumn.pm index ee1ed04..e26b6c2 100644 --- a/lib/DBIx/Class/ResultSetColumn.pm +++ b/lib/DBIx/Class/ResultSetColumn.pm @@ -1,8 +1,15 @@ 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_wantarray'; +use namespace::clean; + +# not importing first() as it will clash with our own method +use List::Util (); =head1 NAME @@ -37,61 +44,86 @@ 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 $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 +131,6 @@ 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(@_) } @@ -118,7 +148,7 @@ 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 @@ -146,7 +176,7 @@ 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 @@ -261,7 +291,7 @@ sub min { =item Arguments: none -=item Return Value: $resultset +=item Return Value: L<$resultset|DBIx::Class::ResultSet> =back @@ -300,7 +330,7 @@ sub max { =item Arguments: none -=item Return Value: $resultset +=item Return Value: L<$resultset|DBIx::Class::ResultSet> =back @@ -339,7 +369,7 @@ sub sum { =item Arguments: none -=item Return Value: $resultset +=item Return Value: L<$resultset|DBIx::Class::ResultSet> =back @@ -376,6 +406,7 @@ sub func { 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; } @@ -388,7 +419,7 @@ sub func { =item Arguments: $function -=item Return Value: $resultset +=item Return Value: L<$resultset|DBIx::Class::ResultSet> =back @@ -398,26 +429,35 @@ 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; + } + + $rs->search( 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(@_); } } @@ -435,24 +475,47 @@ sub throw_exception { 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 = \[ $rsrc->storage->sql_maker->_recurse_fields($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