DBIx::Class::Helper::ResultSet::VirtualView(3pm)

NAME

DBIx::Class::Helper::ResultSet::VirtualView - Clean up your SQL namespace (DEPRECATED)

SYNOPSIS

 # note that this is normally a component for a ResultSet
 package MySchema::ResultSet::Bar;
 use strict;
 use warnings;
 use parent 'DBIx::Class::ResultSet';
 __PACKAGE__->load_components('Helper::ResultSet::VirtualView');
 # and then in code that uses the ResultSet Join with relation x
 my $rs = $schema->resultset('Bar')->search({'x.name' => 'abc'},{ join => 'x' });
 # 'x' now pollutes the query namespace
 # So the following works as expected
 my $ok_rs = $rs->search({'x.other' => 1});
 # But this doesn't: instead of finding a 'Bar' related to two x rows (abc and
 # def) we look for one row with contradictory terms and join in another table
 # (aliased 'x_2') which we never use
 my $broken_rs = $rs->search({'x.name' => 'def'});
 my $rs2 = $rs->as_virtual_view;
 # doesn't work - 'x' is no longer accessible in $rs2, having been sealed away
 my $not_joined_rs = $rs2->search({'x.other' => 1});
 # works as expected: finds a 'table' row related to two x rows (abc and def)
 my $correctly_joined_rs = $rs2->search({'x.name' => 'def'});

DESCRIPTION

This component is will allow you to clean up your SQL namespace. See "NOTE" in DBIx::Class::Helper::ResultSet for a nice way to apply it to your entire schema.

DEPRECATED

This component has been suplanted by DBIx::Class::ResultSet::as_subselect_rs. In the next major version (3) we will begin issuing a warning on it's use. In the major version after that (4) we will remove it entirely.

METHODS

as_virtual_view

Act as a barrier to SQL symbols. The resultset provided will be made into a "virtual view" by including it as a subquery within the from clause. From this point on, any joined tables are inaccessible to ->search on the resultset (as if it were simply where-filtered without joins). See "SYNOPSIS" for example.

NOTE

You don't have to use this as a Component. If you prefer you can use it in the following manner:

 # in code using ResultSet:
 use DBIx::Class:Helper::VirtualView;
 my $new_rs = DBIx::Class::Helper::VirtualView::as_virtual_view($rs);

THANKS

Thanks to ijw from #dbix-class for the idea for this helper (originally called seal), most of the code, and most of the documentation.

AUTHOR

Arthur Axel "fREW" Schmidt <[email protected]>

COPYRIGHT AND LICENSE

This is free software; you can redistribute it and/or modify it under the same terms as the Perl 5 programming language system itself.