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) 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.