DBIx::Class::Helper::ResultSet::SetOperations(3)

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) 2024 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.