Arthur Axel "fREW" Schmidt > DBIx-Class-Helpers-2.019004 > DBIx::Class::Helper::ResultSet::SetOperations

Download:
DBIx-Class-Helpers-2.019004.tar.gz

Dependencies

Annotate this POD

Website

View/Report Bugs
Module Version: 2.019004   Source   Latest Release: DBIx-Class-Helpers-2.023005

NAME ^

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

VERSION ^

version 2.019004

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) 2014 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.

syntax highlighting: