use base 'DBIx::Class';
+use Carp::Clan qw/^DBIx::Class/;
use DBIx::Class::Exception;
use List::Util;
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;
+ my $new_attrs = $new_parent_rs->{attrs} ||= {};
+
+ # since what we do is actually chain to the original resultset, we need to throw
+ # away all selectors (otherwise they'll chain)
+ delete $new_attrs->{$_} for (qw/columns +columns select +select as +as cols include_columns/);
# 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} );
# 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] : $column;
# {collapse} would mean a has_many join was injected, which in turn means
- # we need to group IF WE CAN (only if the column in question is unique)
+ # we need to group *IF WE CAN* (only if the column in question is unique)
if (!$new_attrs->{group_by} && keys %{$orig_attrs->{collapse}}) {
# scan for a constraint that would contain our column only - that'd be proof
if ($col eq $select or $fqcol eq $select) {
$new_attrs->{group_by} = [ $select ];
+ delete $new_attrs->{distinct}; # it is ignored when group_by is present
last;
}
}
+
+ if (!$new_attrs->{group_by}) {
+ 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;
}
-=head2 as_query (EXPERIMENTAL)
+=head2 as_query
=over 4
This is generally used as the RHS for a subquery.
-B<NOTE>: This feature is still experimental.
-
=cut
sub as_query { return shift->_resultset->as_query(@_) }