NAME

DBIx::Class::Helper::ResultSet::Union - Do unions with DBIx::Class

VERSION

version 2.002002

SYNOPSIS

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

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

 ...

 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 create unions 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 union two queries 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 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.

So you might have something like the following sketch autocompletion code:

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

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

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

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

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

METHODS

union

Takes a single ResultSet or an ArrayRef of ResultSets as the parameter.

AUTHOR

  Arthur Axel "fREW" Schmidt <frioux+cpan@gmail.com>

COPYRIGHT AND LICENSE

This software is copyright (c) 2010 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.