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

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)