The database consists of the following:
table 'artist' with columns: artistid, name
- table 'cd' with columns: cdid, artist, title
+ table 'cd' with columns: cdid, artist, title, year
table 'track' with columns: trackid, cd, title
Install DBIx::Class via CPAN should be sufficient.
-=head3 Create the database/tables.
+=head3 Create the database/tables
First make and change the directory:
mkdir app
cd app
+ mkdir db
+ cd db
This example uses SQLite which is a dependency of DBIx::Class, so you
shouldn't have to install extra software.
-Save the following into a example.sql
+Save the following into a example.sql in the directory db
CREATE TABLE artist (
artistid INTEGER PRIMARY KEY,
- name TEXT NOT NULL
+ name TEXT NOT NULL
);
CREATE TABLE cd (
title TEXT NOT NULL
);
-and create the sqlite database file:
+and create the SQLite database file:
-sqlite3 example.db < example.sql
+ sqlite3 example.db < example.sql
=head3 Set up DBIx::Class::Schema
-First, create some dirs and change working directory:
+Change directory back from db to the directory app:
- mkdir MyDatabase
- mkdir MyDatabase/Main
+ cd ../
+
+Now create some more directories:
+
+ mkdir MyApp
+ mkdir MyApp/Schema
+ mkdir MyApp/Schema/Result
+ mkdir MyApp/Schema/ResultSet
Then, create the following DBIx::Class::Schema classes:
-MyDatabase/Main.pm:
-
- package MyDatabase::Main;
+MyApp/Schema.pm:
+
+ package MyApp::Schema;
use base qw/DBIx::Class::Schema/;
- __PACKAGE__->load_classes(qw/Artist Cd Track/);
+ __PACKAGE__->load_namespaces;
1;
-MyDatabase/Main/Artist.pm:
+MyApp/Schema/Result/Artist.pm:
- package MyDatabase::Main::Artist;
- use base qw/DBIx::Class/;
- __PACKAGE__->load_components(qw/Core/);
+ package MyApp::Schema::Result::Artist;
+ use base qw/DBIx::Class::Core/;
__PACKAGE__->table('artist');
__PACKAGE__->add_columns(qw/ artistid name /);
__PACKAGE__->set_primary_key('artistid');
- __PACKAGE__->has_many('cds' => 'MyDatabase::Main::Cd');
+ __PACKAGE__->has_many('cds' => 'MyApp::Schema::Result::Cd');
1;
-MyDatabase/Main/Cd.pm:
+MyApp/Schema/Result/Cd.pm:
- package MyDatabase::Main::Cd;
- use base qw/DBIx::Class/;
- __PACKAGE__->load_components(qw/Core/);
+ package MyApp::Schema::Result::Cd;
+ use base qw/DBIx::Class::Core/;
+ __PACKAGE__->load_components(qw/InflateColumn::DateTime/);
__PACKAGE__->table('cd');
- __PACKAGE__->add_columns(qw/ cdid artist title/);
+ __PACKAGE__->add_columns(qw/ cdid artist title year/);
__PACKAGE__->set_primary_key('cdid');
- __PACKAGE__->belongs_to('artist' => 'MyDatabase::Main::Artist');
- __PACKAGE__->has_many('tracks' => 'MyDatabase::Main::Track');
+ __PACKAGE__->belongs_to('artist' => 'MyApp::Schema::Result::Artist');
+ __PACKAGE__->has_many('tracks' => 'MyApp::Schema::Result::Track');
1;
-MyDatabase/Main/Track.pm:
+MyApp/Schema/Result/Track.pm:
- package MyDatabase::Main::Track;
- use base qw/DBIx::Class/;
- __PACKAGE__->load_components(qw/Core/);
+ package MyApp::Schema::Result::Track;
+ use base qw/DBIx::Class::Core/;
__PACKAGE__->table('track');
- __PACKAGE__->add_columns(qw/ trackid cd title/);
+ __PACKAGE__->add_columns(qw/ trackid cd title /);
__PACKAGE__->set_primary_key('trackid');
- __PACKAGE__->belongs_to('cd' => 'MyDatabase::Main::Cd');
+ __PACKAGE__->belongs_to('cd' => 'MyApp::Schema::Result::Cd');
1;
-=head3 Write a script to insert some records.
+=head3 Write a script to insert some records
insertdb.pl
- #!/usr/bin/perl -w
+ #!/usr/bin/perl
- use MyDatabase::Main;
use strict;
+ use warnings;
- my $schema = MyDatabase::Main->connect('dbi:SQLite:example.db');
+ use MyApp::Schema;
- # here's some of the sql that is going to be generated by the schema
- # INSERT INTO artist VALUES (NULL,'Michael Jackson');
- # INSERT INTO artist VALUES (NULL,'Eminem');
+ my $schema = MyApp::Schema->connect('dbi:SQLite:db/example.db');
my @artists = (['Michael Jackson'], ['Eminem']);
$schema->populate('Artist', [
my @cds;
foreach my $lp (keys %albums) {
- my $artist = $schema->resultset('Artist')->search({
+ my $artist = $schema->resultset('Artist')->find({
name => $albums{$lp}
});
- push @cds, [$lp, $artist->first];
+ push @cds, [$lp, $artist->id];
}
$schema->populate('Cd', [
my @tracks;
foreach my $track (keys %tracks) {
- my $cdname = $schema->resultset('Cd')->search({
+ my $cdname = $schema->resultset('Cd')->find({
title => $tracks{$track},
});
- push @tracks, [$cdname->first, $track];
+ push @tracks, [$cdname->id, $track];
}
$schema->populate('Track',[
@tracks,
]);
-=head3 Create and run the scripts
+=head3 Create and run the test scripts
testdb.pl:
- #!/usr/bin/perl -w
+ #!/usr/bin/perl
- use MyDatabase::Main;
use strict;
+ use warnings;
- my $schema = MyDatabase::Main->connect('dbi:SQLite:example.db');
+ use MyApp::Schema;
+
+ my $schema = MyApp::Schema->connect('dbi:SQLite:db/example.db');
+ # for other DSNs, e.g. MySQL, see the perldoc for the relevant dbd
+ # driver, e.g perldoc L<DBD::mysql>.
get_tracks_by_cd('Bad');
get_tracks_by_artist('Michael Jackson');
},
{
join => [qw/ cd /],
- prefetch => [qw/ cd /]
}
);
while (my $track = $rs->next) {
}
print "\n";
}
-
-
+
+
sub get_cd_by_track {
my $tracktitle = shift;
print "get_cd_by_track($tracktitle):\n";
my $cd = $rs->first;
print $cd->title . "\n\n";
}
-
+
sub get_cds_by_artist {
my $artistname = shift;
print "get_cds_by_artist($artistname):\n";
},
{
join => [qw/ artist /],
- prefetch => [qw/ artist /]
}
);
while (my $cd = $rs->next) {
=head1 Notes
+A reference implementation of the database and scripts in this example
+are available in the main distribution for DBIx::Class under the
+directory F<examples/Schema>.
+
With these scripts we're relying on @INC looking in the current
-working directory. You may want to add the MyDatabase namespaces to
+working directory. You may want to add the MyApp namespaces to
@INC in a different way when it comes to deployment.
-The testdb.pl script is an excellent start for testing your database
+The F<testdb.pl> script is an excellent start for testing your database
model.
+This example uses L<DBIx::Class::Schema/load_namespaces> to load in the
+appropriate L<Result|DBIx::Class::Manual::ResultClass> classes from the
+C<MyApp::Schema::Result> namespace, and any required
+L<ResultSet|DBIx::Class::ResultSet> classes from the
+C<MyApp::Schema::ResultSet> namespace (although we created the directory
+in the directions above we did not add, or need to add, any resultset
+classes).
+
=head1 TODO
=head1 AUTHOR
sc_ from irc.perl.org#dbix-class
Kieren Diment <kd@totaldatasolution.com>
+ Nigel Metheringham <nigelm@cpan.org>
=cut