debian man page for dbix::class::helper::resultset::virtualview

DBIx::Class::Helper::ResultSet::VirtualView(3pm)	User Contributed Perl Documentation	  DBIx::Class::Helper::ResultSet::VirtualView(3pm)

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

VERSION
       version 2.013002

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 <frioux+cpan@gmail.com>

COPYRIGHT AND LICENSE
       This software is copyright (c) 2012 by Arthur Axel "fREW" Schmidt.

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

perl v5.14.2							    2012-06-18			  DBIx::Class::Helper::ResultSet::VirtualView(3pm)