-=head1 Introduction.
+=head1 NAME
-So, you are bored with SQL, and want a native perl interface for your classes?
-Or you've been doing this for a while with L<Class::DBI>, and think there's
-a better way? You've come to the right place. Let's look at how you can set
-and use your first native DBIx::Class tree.
+DBIx::Class::Manual::Intro - Introduction to DBIx::Class
-First we'll see how you can set up your classes yourself. If you want them
-to be auto-discovered, just skip to the next section, which shows you how
-to use DBIx::Class::Loader.
+=head1 INTRODUCTION
+
+So, you are bored with SQL, and want a native Perl interface for your
+database? Or you've been doing this for a while with L<Class::DBI>,
+and think there's a better way? You've come to the right place. Let's
+look at how you can set and use your first native L<DBIx::Class> tree.
+
+First we'll see how you can set up your classes yourself. If you want
+them to be auto-discovered, just skip to the next section, which shows
+you how to use L<DBIx::Class::Loader>.
=head2 Setting it up manually
First, you'll need a base class. It should inherit from DBIx::Class
like this:
- package MyApp::DB
- use base qw/DBIx::Class/;
+ package MyApp::DB;
+ use base qw/DBIx::Class/;
-You will also want to load some of L<DBIx::Class>'s components.
-L<DBIx::Class::Core> provides a good basic set. In addition you'll
+You will also want to load some of L<DBIx::Class>'s components.
+L<DBIx::Class::Core> provides a good basic set. In addition you'll
have to use either L<DBIx::Class::Schema> or L<DBIx::Class::DB> We'll
-use DB in this introduction, since it involves less magic. Schema is
-mostly useful if you want to use multiple database connections.
+use C<DB> in this introduction, since it involves less magic.
+L<Schema> is mostly useful if you want to use multiple database
+connections.
- __PACKAGE__->load_components(qw/Core DB/);
+ __PACKAGE__->load_components(qw/Core DB/);
If you want serial/auto-incremental primary keys, you'll need to add
-the apropriate component for your db as well, for example
+the apropriate component for your db as well, for example. The
+L<DBIx::Class::PK::Auto> modules help L<DBIx::Class> keep up with
+newly generated keys in auto increment database fields.
- __PACKAGE__->load_components(qw/Core DB PK::Auto::SQLite/);
+ __PACKAGE__->load_components(qw/PK::Auto::SQLite Core DB/);
Once you've loaded the components, it's time to set up your connection:
- __PACKAGE__->connection('dbi:SQLite:/home/me/myapp/my.db');
+ __PACKAGE__->connection('dbi:SQLite:/home/me/myapp/my.db');
-This method is similar to the normal L<DBI>, and can take user/pass/dbi
-attribute hash as well as the dsn.
+This method is similar to the normal L<DBI>, and can take username,
+password, and L<DBI> attribute hash as well as the DSN.
With that out of the way, we can define our first table class:
- package MyApp::DB::Frob
-
- use base qw/MyApp::DB/;
+ package MyApp::DB::Album;
+ use base qw/MyApp::DB/;
Then we specify which table it uses,
- __PACKAGE__->table('frob');
+ __PACKAGE__->table('album');
and specify which columns it has.
- __PACKAGE__->add_columns(qw/id foo bar/);
+ __PACKAGE__->add_columns(qw/albumID artist title label year/);
-This will automatically create accessors for each of the columns, so that
-you can read/update the values in rows you've retrieved.
+This will automatically create accessors for each of the columns, so
+that you can read/update the values in rows you've retrieved.
Also, you need to tell it which column is the primary key:
- __PACKAGE__->set_primary_key('id');
+ __PACKAGE__->set_primary_key('albumID');
If you have multiple primary keys, just pass a list instead.
-That's pretty much all you need for a basic setup. If you have more advanced
-needs like using more than 1 database connections for the same class, see
-L<DBIx::Class::Schema>.
+That's pretty much all you need for a basic setup. If you have more
+advanced needs like using more than one database connection for the
+same class, see L<DBIx::Class::Schema>.
-=head2 Using L<DBIx::Class::Loader>.
+=head2 Using L<DBIx::Class::Loader>
-This is an additional class, and not part of the DBIx::Class distribution.
-Like L<Class::DBI::Loader>, it inspects your database, and automatically
-creates classes for all the tables in your database. Here's a simple setup:
+This is an additional class, and not part of the L<DBIx::Class>
+distribution. Like L<Class::DBI::Loader>, it inspects your database,
+and automatically creates classes for all the tables in your
+database. Here's a simple setup:
- package MyApp::DB;
-
- use DBIx::Class::Loader;
+ package MyApp::DB;
+ use DBIx::Class::Loader;
+
+ my $loader = DBIx::Class::Loader->new(
+ dsn => 'dbi:SQLite:/home/me/myapp/my.db',
+ namespace => 'MyApp::DB'
+ );
- my $loader=DBIx::Class::Loader->new(
- dsn => 'dbi:SQLite:/home/me/myapp/my.db',
- namespace => 'MyApp::DB');
- 1;
+ 1;
-This should be equivalent to the manual in the section above.
-L<DBIx::Class::Loader> takes lots of other options. For more information,
-consult the reference documentation.
+This should be equivalent to the manual in the section above.
+L<DBIx::Class::Loader> takes lots of other options. For more
+information, consult its documentation.
-=head2 Basic Usage
+=head2 Basic usage
-Once you've defined the basic classes, you can start interacting with your
-database. The simplest way to get a column is by primary key:
+Once you've defined the basic classes, you can start interacting with
+your database. The simplest way to get a column is by primary key:
- my $frob=MyApp::DB::Frob->find(14);
+ my $albumID = 14;
+ my $album = MyApp::DB::Album->find($albumID);
-This will run a select with id=14 in the WHERE clause, and return an instance
-of MyApp::DB::Frob that represents this row. Once you have that row, you can
-access and update columns
+This will run a select with C<albumID = 14> in the C<WHERE> clause,
+and return an instance of C<MyApp::DB::Artist> that represents this
+row. Once you have that row, you can access and update columns:
- my $val=$frob->bar;
- $frob->bar(14);
+ $album->title('Physical Graffiti');
+ my $title = $album->title; # $title holds 'Physical Graffiti'
-or if you prefer, you can use the set_column/get_column accessors instead
-of the autogenerated accessors based on your column names.
+If you prefer, you can use the C<set_column> and C<get_column>
+accessors instead:
-Just like with L<Class::DBI>, you do an 'update' to commit your changes
-to the database:
+ $album->set_column('title', 'Presence');
+ $title = $album->get_column('title');
- $frob->update;
+Just like with L<Class::DBI>, you do an C<update> to commit your
+changes to the database:
+
+ $album->update;
If needed, you can drop your local changes instead like this:
- $frob->discard_changes if $frob->is_changed;
+ $album->discard_changes if $album->is_changed;
+
+As you can see, C<is_changed> allows you to check if there are local
+changes to your object.
+
+=head2 Adding and removing rows
+
+To create a new record in the database, you can use the C<create>
+method from L<DBIx::Class::Row>. It returns a
+L<DBIx::Class::ResultSet> object that can be used to access the data
+in the new record.
-As you can see, is_changed allows you to check if there are local changes to
-your object.
+ my $new_album = MyApp::DB::Album->create({
+ title => 'Wish You Were Here',
+ artist => 'Pink Floyd'
+ });
-=head2 Adding and removing rows.
+Now you can add data to the new record:
-To make a new row, and put it into the database, you can use the 'create'
-method from L<DBIx::Class::Row>
+ $new_album->label('Capitol');
+ $new_album->year('1975');
- my $new_thingie=MyApp::DB::Frob->create({
- foo=>'homer',
- bar=>'bart' });
+Likewise, you can remove if from the database like this:
-likewise, you can remove if from the database like this:
+ $new_album->delete;
- $new_thingie->delete();
+or even without retrieving first. This operation takes the same kind
+of arguments as a search.
-or even without retrieving first. This operation takes the same kind of
-arguments as a search.
+ MyApp::DB::Album->delete({ artist => 'Falco' });
- MyApp::DB::Frob->delete({foo=>'bart'});
+=head2 Finding your objects
-=head2 Finding your objects.
+L<DBIx::Class> provides a few different ways to retrieve data from
+your database. The simplest looks something like this:
-DBIx::Class provides a few different ways to retrieve data from your database.
-The simplest looks something like this:
+ my $iter = MyApp::DB::Album->search( artist => 'Santana' );
- $rs=MyApp::DB::Frob->search(foo=>'bart');
+Note that all the C<search> methods return a L<DBIx::Class::ResultSet>
+object in scalar context. So, if you want the first album:
-note that all the search methods return a recordset in scalar context or
-a list containing all the elements in list context.
+ my $album = $iter->first;
-We also provide a handy shortcut for doing a like search:
+In list context, the C<search> methods return all of the matching
+rows:
- $rs=MyApp::DB::Frob->search_like(foo=>'bar%');
+ my @albums = MyApp::DB::Album->search( artist => 'Santana' );
-Or you can provide your own handmade WHERE clause, like
+We also provide a handy shortcut for doing a C<LIKE> search:
+
+ my $iter = MyApp::DB::Album->search_like( artist => 'Jimi%' );
+
+Or you can provide your own handmade C<WHERE> clause, like:
- $rs=MyApp::DB::Frob->search_literal('foo=?','bart');
+ my $iter = MyApp::DB::Album->search_literal( 'artist = ?', 'Peter Frampton' );
+
+The preferred way to generate complex queries is to provide a
+L<SQL::Abstract> construct to C<search>:
+
+ my $iter = MyApp::DB::Album->search({
+ artist => { '!=', 'Janis Joplin' },
+ year => { '<' => 1980 },
+ id => [ 1, 14, 15, 65, 43 ]
+ });
+
+For more examples of complex searches, see
+L<DBIx::Class::Manual::Cookbook>.
+
+The search can also be modified by passing another hash with
+attributes:
+
+ my $iter = MyApp::DB::Album->search(
+ { artist => 'Bob Marley' },
+ { page => 1, rows => 2, order_by => 'year' }
+ );
+
+For a complete overview of the available attributes, see
+L<DBIx::Class::ResultSet/ATTRIBUTES>.
-The other way to provide more complex queries, is to provide a
-L<SQL::Abstract> construct to search:
+=head1 SEE ALSO
- $rs=MyApp::DB::Frob->search({
- bar=>{'>' => 10 },
- foo=>{'!=','bart'},
- id => [1,14,15,65,43]
- });
+=over 4
-The search can also be modifyed by passing another hash with attributes:
+=item * L<DBIx::Class::Manual::Cookbook>
- $rs=MyApp::DB::Frob->search( {foo=>'bart'},
- { page=>1, rows=>2, order_by=>'bar' } );
+=item * L<DBIx::Class::Manual::FAQ>
-For a complete overview over the available attributes, see
-L<DBIx::Class::ResultSet>
+=back
=cut
projects / dbsrgits/DBIx-Class.git / blobdiff