dbix::class::helper::resultset::setoperations(3pm) [debian man page]

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

NAME

       DBIx::Class::Helper::ResultSet::SetOperations - Do set operations with DBIx::Class

VERSION

       version 2.013002

SYNOPSIS

	package MyApp::Schema::ResultSet::Foo;

	__PACKAGE__->load_components(qw{Helper::ResultSet::SetOperations});

	...

	1;

       And then elsewhere, like in a controller:

	my $rs1 = $rs->search({ foo => 'bar' });
	my $rs2 = $rs->search({ baz => 'biff' });
	for ($rs1->union($rs2)->all) { ... }

DESCRIPTION

       This component allows you to use various set operations with your ResultSets.  See "NOTE" in DBIx::Class::Helper::ResultSet for a nice way
       to apply it to your entire schema.

       Component throws exceptions if ResultSets have different ResultClasses or different "Columns Specs."

       The basic idea here is that in SQL if you use a set operation they must be selecting the same columns names, so that the results will all
       match.  The deal with the ResultClasses is that DBIC needs to inflate the results the same for the entire ResultSet, so if one were to try
       to apply something like a union in a table with the same column name but different classes DBIC wouldn't be doing what you would expect.

       A nice way to use this is with DBIx::Class::ResultClass::HashRefInflator.

       You might have something like the following sketch autocompletion code:

	my $rs1 = $schema->resultset('Album')->search({
	   name => { -like => "$input%" }
	}, {
	  columns => [qw( id name ), {
	     tablename => ['?', [{} => 'album']],
	  }],
	});

	my $rs2 = $schema->resultset('Artist')->search({
	   name => { -like => "$input%" }
	}, {
	  columns => [qw( id name ), {
	     tablename => ['?', [{} => 'artist']],
	  }],
	});

	my $rs3 = $schema->resultset('Song')->search({
	   name => { -like => "$input%" }
	}, {
	  columns => [qw( id name ), {
	     tablename => ['?', [{} => 'song']],
	  }],
	});

	$_->result_class('DBIx::Class::ResultClass::HashRefInflator')
	  for ($rs1, $rs2, $rs3);

	my $data = [$rs1->union([$rs2, $rs3])->all];

METHODS

   union
   union_all
   intersect
   intersect_all
   except
   except_all
       All of these methods take a single ResultSet or an ArrayRef of ResultSets as the parameter only parameter.

       On Oracle "except" will issue a "MINUS" operation.

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::SetOperations(3pm)

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)