From: Jess Robinson Date: Tue, 21 Mar 2006 22:46:35 +0000 (+0000) Subject: New version X-Git-Tag: v0.06000~38 X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?a=commitdiff_plain;h=3f34147465dbc402336f143fce45c98fc178beb1;p=dbsrgits%2FDBIx-Class.git New version --- diff --git a/lib/DBIx/Class/Manual/Example.pod b/lib/DBIx/Class/Manual/Example.pod new file mode 100644 index 0000000..e2a5166 --- /dev/null +++ b/lib/DBIx/Class/Manual/Example.pod @@ -0,0 +1,355 @@ +=head1 NAME + +DBIx::Class::Manual::Example - Simple CD database example + +=head1 DESCRIPTION + +This tutorial will guide you through the proeccess of setting up and +testing a very basic CD database using SQLite, with DBIx::Class::Schema +as the database frontend. + +The database consists of the following: + + table 'artist' with columns: artistid, name + table 'cd' with columns: cdid, artist, title + table 'track' with columns: trackid, cd, title + + +And these rules exists: + + one artist can have many cds + one cd belongs to one artist + one cd can have many tracks + one track belongs to one cd + + +=head2 Installation + +Install DBIx::Class via CPAN should be sufficient. + +=head3 Create the database/tables. + +First make and change the directory: + + mkdir app + cd app + +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 + + CREATE TABLE artist ( + 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); + + CREATE TABLE track ( + trackid INTEGER PRIMARY KEY, + cd INTEGER NOT NULL REFERENCES cd(cdid), + title TEXT NOT NULL) ; + +and create the sqlite database file: + +sqlite3 example.db < example.sql + +=head3 Set up DBIx::Class::Schema + +First, create some dirs and change working directory: + + mkdir MyDatabase + mkdir MyDatabase/Main + +Then, create the following DBIx::Class::Schema classes: + +MyDatabase/Main.pm: + + package MyDatabase::Main; + use base qw/DBIx::Class::Schema/; + __PACKAGE__->load_classes(qw/Artist Cd Track/); + + 1; + + +MyDatabase/Main/Artist.pm: + + package MyDatabase::Main::Artist; + use base qw/DBIx::Class/; + __PACKAGE__->load_components(qw/Core/); + __PACKAGE__->table('artist'); + __PACKAGE__->add_columns(qw/ artistid name /); + __PACKAGE__->set_primary_key('artistid'); + __PACKAGE__->has_many('cds' => 'MyDatabase::Main::Cd'); + + 1; + + +MyDatabase/Main/Cd.pm: + + package MyDatabase::Main::Cd; + use base qw/DBIx::Class/; + __PACKAGE__->load_components(qw/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'); + + 1; + + +MyDatabase/Main/Track.pm: + + package MyDatabase::Main::Track; + use base qw/DBIx::Class/; + __PACKAGE__->load_components(qw/Core/); + __PACKAGE__->table('track'); + __PACKAGE__->add_columns(qw/ trackid cd title/); + __PACKAGE__->set_primary_key('trackid'); + __PACKAGE__->belongs_to('cd' => 'MyDatabase::Main::Cd'); + + 1; + + +=head3 Write a script to insert some records. + +insertdb.pl + + #!/usr/bin/perl -w + + use MyDatabase::Main; + use strict; + + my $schema = MyDatabase::Main->connect('dbi:SQLite:example.db'); + + # 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 @artists = (['Michael Jackson'], ['Eminem']); + $schema->populate('Artist', [ + [qw/name/], + @artists, + ]); + + my %albums = ( + '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]; + } + + $schema->populate('Cd', [ + [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', + ); + + my @tracks; + foreach my $track (keys %tracks) { + my $cdname = $schema->resultset('Cd')->search({ + title => $tracks{$track}, + }); + push @tracks, [$cdname->first, $track]; + } + + $schema->populate('Track',[ + [qw/cd title/], + @tracks, + ]); + +=head3 Create and run the scripts + +testdb.pl: + + #!/usr/bin/perl -w + + use MyDatabase::Main; + use strict; + + my $schema = MyDatabase::Main->connect('dbi:SQLite:example.db'); + + get_tracks_by_cd('Bad'); + get_tracks_by_artist('Michael Jackson'); + + get_cd_by_track('Stan'); + get_cds_by_artist('Michael Jackson'); + + get_artist_by_track('Dirty Diana'); + get_artist_by_cd('The Marshall Mathers LP'); + + + 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"; + } + 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"; + } + 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"; + } + + 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"; + } + 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"; + } + + 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"; + } + + + +It should output: + + get_tracks_by_cd(Bad): + Dirty Diana + Smooth Criminal + Leave Me Alone + + get_tracks_by_artist(Michael Jackson): + Beat it + Billie Jean + Dirty Diana + Smooth Criminal + Leave Me Alone + + get_cd_by_track(Stan): + The Marshall Mathers LP + + get_cds_by_artist(Michael Jackson): + Thriller + Bad + + get_artist_by_track(Dirty Diana): + Michael Jackson + + get_artist_by_cd(The Marshall Mathers LP): + Eminem + +=head1 Notes + +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 deployemnt. + +The testdb.pl script is an excellent start for testing your database +model. + +=head1 TODO + +=head1 AUTHOR + + sc_ from irc.perl.org#dbix-class + Kieren Diment + +=cut