NAME

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

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) 2015 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 v5.20.2                                201DBIx::Class::Helper::ResultSet::SetOperations(3pm)