3 So, you are bored with SQL, and want a native perl interface for your classes?
4 Or you've been doing this for a while with L<Class::DBI>, and think there's
5 a better way? You've come to the right place. Let's look at how you can set
6 and use your first native DBIx::Class tree.
8 First we'll see how you can set up your classes yourself. If you want them
9 to be auto-discovered, just skip to the next section, which shows you how
10 to use DBIx::Class::Loader.
12 =head2 Setting it up manually
14 First, you'll need a base class. It should inherit from DBIx::Class
18 use base qw/DBIx::Class/;
20 You will also want to load some of L<DBIx::Class>'s components.
21 L<DBIx::Class::Core> provides a good basic set. In addition you'll
22 have to use either L<DBIx::Class::Schema> or L<DBIx::Class::DB> We'll
23 use DB in this introduction, since it involves less magic. Schema is
24 mostly useful if you want to use multiple database connections.
26 __PACKAGE__->load_components(qw/Core DB/);
28 If you want serial/auto-incremental primary keys, you'll need to add
29 the apropriate component for your db as well, for example
31 __PACKAGE__->load_components(qw/PK::Auto::SQLite Core DB/);
33 Once you've loaded the components, it's time to set up your connection:
35 __PACKAGE__->connection('dbi:SQLite:/home/me/myapp/my.db');
37 This method is similar to the normal L<DBI>, and can take user/pass/dbi
38 attribute hash as well as the dsn.
40 With that out of the way, we can define our first table class:
42 package MyApp::DB::Frob
44 use base qw/MyApp::DB/;
46 Then we specify which table it uses,
48 __PACKAGE__->table('frob');
50 and specify which columns it has.
52 __PACKAGE__->add_columns(qw/id foo bar/);
54 This will automatically create accessors for each of the columns, so that
55 you can read/update the values in rows you've retrieved.
57 Also, you need to tell it which column is the primary key:
59 __PACKAGE__->set_primary_key('id');
61 If you have multiple primary keys, just pass a list instead.
63 That's pretty much all you need for a basic setup. If you have more advanced
64 needs like using more than 1 database connections for the same class, see
65 L<DBIx::Class::Schema>.
67 =head2 Using L<DBIx::Class::Loader>.
69 This is an additional class, and not part of the DBIx::Class distribution.
70 Like L<Class::DBI::Loader>, it inspects your database, and automatically
71 creates classes for all the tables in your database. Here's a simple setup:
75 use DBIx::Class::Loader;
77 my $loader=DBIx::Class::Loader->new(
78 dsn => 'dbi:SQLite:/home/me/myapp/my.db',
79 namespace => 'MyApp::DB');
82 This should be equivalent to the manual in the section above.
83 L<DBIx::Class::Loader> takes lots of other options. For more information,
84 consult the reference documentation.
88 Once you've defined the basic classes, you can start interacting with your
89 database. The simplest way to get a column is by primary key:
91 my $frob=MyApp::DB::Frob->find(14);
93 This will run a select with id=14 in the WHERE clause, and return an instance
94 of MyApp::DB::Frob that represents this row. Once you have that row, you can
95 access and update columns
100 or if you prefer, you can use the set_column/get_column accessors instead
101 of the autogenerated accessors based on your column names.
103 Just like with L<Class::DBI>, you do an 'update' to commit your changes
108 If needed, you can drop your local changes instead like this:
110 $frob->discard_changes if $frob->is_changed;
112 As you can see, is_changed allows you to check if there are local changes to
115 =head2 Adding and removing rows.
117 To make a new row, and put it into the database, you can use the 'create'
118 method from L<DBIx::Class::Row>
120 my $new_thingie=MyApp::DB::Frob->create({
124 likewise, you can remove if from the database like this:
126 $new_thingie->delete();
128 or even without retrieving first. This operation takes the same kind of
129 arguments as a search.
131 MyApp::DB::Frob->delete({foo=>'bart'});
133 =head2 Finding your objects.
135 DBIx::Class provides a few different ways to retrieve data from your database.
136 The simplest looks something like this:
138 $rs=MyApp::DB::Frob->search(foo=>'bart');
140 note that all the search methods return a recordset in scalar context or
141 a list containing all the elements in list context.
143 We also provide a handy shortcut for doing a like search:
145 $rs=MyApp::DB::Frob->search_like(foo=>'bar%');
147 Or you can provide your own handmade WHERE clause, like
149 $rs=MyApp::DB::Frob->search_literal('foo=?','bart');
151 The other way to provide more complex queries, is to provide a
152 L<SQL::Abstract> construct to search:
154 $rs=MyApp::DB::Frob->search({
157 id => [1,14,15,65,43]
160 The search can also be modifyed by passing another hash with attributes:
162 $rs=MyApp::DB::Frob->search( {foo=>'bart'},
163 { page=>1, rows=>2, order_by=>'bar' } );
165 For a complete overview over the available attributes, see
166 L<DBIx::Class::ResultSet>