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
+ artistid INTEGER PRIMARY KEY,
+ name TEXT NOT NULL
);
CREATE TABLE cd (
- cdid INTEGER PRIMARY KEY,
- artist INTEGER NOT NULL REFERENCES artist(artistid),
- title TEXT NOT NULL);
+ cdid INTEGER PRIMARY KEY,
+ artist INTEGER NOT NULL REFERENCES artist(artistid),
+ title TEXT NOT NULL
+ );
CREATE TABLE track (
- trackid INTEGER PRIMARY KEY,
- cd INTEGER NOT NULL REFERENCES cd(cdid),
- title TEXT NOT NULL) ;
+ trackid INTEGER PRIMARY KEY,
+ cd INTEGER NOT NULL REFERENCES cd(cdid),
+ title TEXT NOT NULL
+ );
and create the sqlite database file:
=head3 Set up DBIx::Class::Schema
-First, create some dirs and change working directory:
+Change directory back from db to the directory app:
+
+ cd ../
+
+Now create some more directories:
mkdir MyDatabase
mkdir MyDatabase/Main
+ mkdir MyDatabase/Main/Result
+ mkdir MyDatabase/Main/ResultSet
Then, create the following DBIx::Class::Schema classes:
package MyDatabase::Main;
use base qw/DBIx::Class::Schema/;
- __PACKAGE__->load_classes(qw/Artist Cd Track/);
+ __PACKAGE__->load_namespaces;
1;
-MyDatabase/Main/Artist.pm:
+MyDatabase/Main/Result/Artist.pm:
- package MyDatabase::Main::Artist;
+ package MyDatabase::Main::Result::Artist;
use base qw/DBIx::Class/;
- __PACKAGE__->load_components(qw/Core/);
+ __PACKAGE__->load_components(qw/PK::Auto 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' => 'MyDatabase::Main::Result::Cd');
1;
-MyDatabase/Main/Cd.pm:
+MyDatabase/Main/Result/Cd.pm:
- package MyDatabase::Main::Cd;
+ package MyDatabase::Main::Result::Cd;
use base qw/DBIx::Class/;
- __PACKAGE__->load_components(qw/Core/);
+ __PACKAGE__->load_components(qw/PK::Auto Core/);
__PACKAGE__->table('cd');
__PACKAGE__->add_columns(qw/ cdid artist title/);
__PACKAGE__->set_primary_key('cdid');
- __PACKAGE__->belongs_to('artist' => 'MyDatabase::Main::Artist');
- __PACKAGE__->has_many('tracks' => 'MyDatabase::Main::Track');
+ __PACKAGE__->belongs_to('artist' => 'MyDatabase::Main::Result::Artist');
+ __PACKAGE__->has_many('tracks' => 'MyDatabase::Main::Result::Track');
1;
-MyDatabase/Main/Track.pm:
+MyDatabase/Main/Result/Track.pm:
- package MyDatabase::Main::Track;
+ package MyDatabase::Main::Result::Track;
use base qw/DBIx::Class/;
- __PACKAGE__->load_components(qw/Core/);
+ __PACKAGE__->load_components(qw/PK::Auto Core/);
__PACKAGE__->table('track');
__PACKAGE__->add_columns(qw/ trackid cd title/);
__PACKAGE__->set_primary_key('trackid');
- __PACKAGE__->belongs_to('cd' => 'MyDatabase::Main::Cd');
+ __PACKAGE__->belongs_to('cd' => 'MyDatabase::Main::Result::Cd');
1;
use MyDatabase::Main;
use strict;
- my $schema = MyDatabase::Main->connect('dbi:SQLite:example.db');
+ my $schema = MyDatabase::Main->connect('dbi:SQLite:db/example.db');
# here's some of the sql that is going to be generated by the schema
# INSERT INTO artist VALUES (NULL,'Michael Jackson');
my @artists = (['Michael Jackson'], ['Eminem']);
$schema->populate('Artist', [
- [qw/name/],
- @artists,
+ [qw/name/],
+ @artists,
]);
my %albums = (
- 'Thriller' => 'Michael Jackson',
- 'Bad' => 'Michael Jackson',
- 'The Marshall Mathers LP' => 'Eminem',
- );
+ 'Thriller' => 'Michael Jackson',
+ 'Bad' => 'Michael Jackson',
+ 'The Marshall Mathers LP' => 'Eminem',
+ );
my @cds;
foreach my $lp (keys %albums) {
- my $artist = $schema->resultset('Artist')->search({
- name => $albums{$lp}
- });
- push @cds, [$lp, $artist->first];
+ my $artist = $schema->resultset('Artist')->search({
+ name => $albums{$lp}
+ });
+ push @cds, [$lp, $artist->first];
}
$schema->populate('Cd', [
- [qw/title artist/],
- @cds,
+ [qw/title artist/],
+ @cds,
]);
my %tracks = (
- 'Beat It' => 'Thriller',
- 'Billie Jean' => 'Thriller',
- 'Dirty Diana' => 'Bad',
- 'Smooth Criminal' => 'Bad',
- 'Leave Me Alone' => 'Bad',
- 'Stan' => 'The Marshall Mathers LP',
- 'The Way I Am' => 'The Marshall Mathers LP',
+ 'Beat It' => 'Thriller',
+ 'Billie Jean' => 'Thriller',
+ 'Dirty Diana' => 'Bad',
+ 'Smooth Criminal' => 'Bad',
+ 'Leave Me Alone' => 'Bad',
+ 'Stan' => 'The Marshall Mathers LP',
+ 'The Way I Am' => 'The Marshall Mathers LP',
);
my @tracks;
foreach my $track (keys %tracks) {
- my $cdname = $schema->resultset('Cd')->search({
- title => $tracks{$track},
- });
- push @tracks, [$cdname->first, $track];
+ my $cdname = $schema->resultset('Cd')->search({
+ title => $tracks{$track},
+ });
+ push @tracks, [$cdname->first, $track];
}
$schema->populate('Track',[
- [qw/cd title/],
- @tracks,
+ [qw/cd title/],
+ @tracks,
]);
-=head3 Create and run the scripts
+=head3 Create and run the test scripts
testdb.pl:
use MyDatabase::Main;
use strict;
- my $schema = MyDatabase::Main->connect('dbi:SQLite:example.db');
+ my $schema = MyDatabase::Main->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');
sub get_tracks_by_cd {
- my $cdtitle = shift;
- print "get_tracks_by_cd($cdtitle):\n";
- my $rs = $schema->resultset('Track')->search(
- {
- 'cd.title' => $cdtitle
- },
- {
- join => [qw/ cd /],
- prefetch => [qw/ cd /]
- }
- );
- while (my $track = $rs->next) {
- print $track->title . "\n";
+ my $cdtitle = shift;
+ print "get_tracks_by_cd($cdtitle):\n";
+ my $rs = $schema->resultset('Track')->search(
+ {
+ 'cd.title' => $cdtitle
+ },
+ {
+ join => [qw/ cd /],
}
- print "\n";
+ );
+ while (my $track = $rs->next) {
+ print $track->title . "\n";
+ }
+ print "\n";
}
sub get_tracks_by_artist {
- my $artistname = shift;
- print "get_tracks_by_artist($artistname):\n";
- my $rs = $schema->resultset('Track')->search(
- {
- 'artist.name' => $artistname
- },
- {
- join => {
- 'cd' => 'artist'
- },
- }
- );
- while (my $track = $rs->next) {
- print $track->title . "\n";
+ my $artistname = shift;
+ print "get_tracks_by_artist($artistname):\n";
+ my $rs = $schema->resultset('Track')->search(
+ {
+ 'artist.name' => $artistname
+ },
+ {
+ join => {
+ 'cd' => 'artist'
+ },
}
- print "\n";
+ );
+ while (my $track = $rs->next) {
+ print $track->title . "\n";
+ }
+ print "\n";
}
-
sub get_cd_by_track {
- my $tracktitle = shift;
- print "get_cd_by_track($tracktitle):\n";
- my $rs = $schema->resultset('Cd')->search(
- {
- 'tracks.title' => $tracktitle
- },
- {
- join => [qw/ tracks /],
- }
- );
- my $cd = $rs->first;
- print $cd->title . "\n\n";
+ my $tracktitle = shift;
+ print "get_cd_by_track($tracktitle):\n";
+ my $rs = $schema->resultset('Cd')->search(
+ {
+ 'tracks.title' => $tracktitle
+ },
+ {
+ join => [qw/ tracks /],
+ }
+ );
+ my $cd = $rs->first;
+ print $cd->title . "\n\n";
}
sub get_cds_by_artist {
- my $artistname = shift;
- print "get_cds_by_artist($artistname):\n";
- my $rs = $schema->resultset('Cd')->search(
- {
- 'artist.name' => $artistname
- },
- {
- join => [qw/ artist /],
- prefetch => [qw/ artist /]
- }
- );
- while (my $cd = $rs->next) {
- print $cd->title . "\n";
+ my $artistname = shift;
+ print "get_cds_by_artist($artistname):\n";
+ my $rs = $schema->resultset('Cd')->search(
+ {
+ 'artist.name' => $artistname
+ },
+ {
+ join => [qw/ artist /],
}
- print "\n";
+ );
+ while (my $cd = $rs->next) {
+ print $cd->title . "\n";
+ }
+ print "\n";
}
sub get_artist_by_track {
- my $tracktitle = shift;
- print "get_artist_by_track($tracktitle):\n";
- my $rs = $schema->resultset('Artist')->search(
- {
- 'tracks.title' => $tracktitle
- },
- {
- join => {
- 'cds' => 'tracks'
- }
- }
- );
- my $artist = $rs->first;
- print $artist->name . "\n\n";
+ my $tracktitle = shift;
+ print "get_artist_by_track($tracktitle):\n";
+ my $rs = $schema->resultset('Artist')->search(
+ {
+ 'tracks.title' => $tracktitle
+ },
+ {
+ join => {
+ 'cds' => 'tracks'
+ }
+ }
+ );
+ my $artist = $rs->first;
+ print $artist->name . "\n\n";
}
sub get_artist_by_cd {
- my $cdtitle = shift;
- print "get_artist_by_cd($cdtitle):\n";
- my $rs = $schema->resultset('Artist')->search(
- {
- 'cds.title' => $cdtitle
- },
- {
- join => [qw/ cds /],
- }
- );
- my $artist = $rs->first;
- print $artist->name . "\n\n";
+ my $cdtitle = shift;
+ print "get_artist_by_cd($cdtitle):\n";
+ my $rs = $schema->resultset('Artist')->search(
+ {
+ 'cds.title' => $cdtitle
+ },
+ {
+ join => [qw/ cds /],
+ }
+ );
+ my $artist = $rs->first;
+ print $artist->name . "\n\n";
}
=head1 Notes
+A reference implentation of the database and scripts in this example
+are available in the main distribution for DBIx::Class under the
+directory t/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
@INC in a different way when it comes to deployment.
The testdb.pl script is an excellent start for testing your database
model.
+This example uses load_namespaces to load in the appropriate Row classes
+from the MyDatabase::Main::Result namespace, and any required resultset
+classes from the MyDatabase::Main::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