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.
25 __PACKAGE__->load_components(qw/Core DB/);
27 If you want serial/auto-incremental primary keys, you'll need to add
28 the apropriate component for your db as well, for example
30 __PACKAGE__->load_components(qw/Core DB PK::Auto::SQLite/);
32 Once you've loaded the components, it's time to set up your connection:
34 __PACKAGE__->connection('dbi:SQLite:/home/me/myapp/my.db');
36 This method is similar to the normal L<DBI>, and can take user/pass/dbi
37 attribute hash as well as the dsn.
39 With that out of the way, we can define our first table class:
41 package MyApp::DB::Frob
43 use base qw/MyApp::DB/;
45 Then we specify which table it uses,
47 __PACKAGE__->table('frob');
49 and specify which columns it has.
51 __PACKAGE__->add_columns(qw/id foo bar/);
53 This will automatically create accessors for each of the columns, so that
54 you can read/update the values in rows you've retrieved.
56 Also, you need to tell it which column is the primary key:
58 __PACKAGE__->set_primary_key('id');
60 If you have multiple primary keys, just pass a list instead.
62 That's pretty much all you need for a basic setup. If you have more advanced
63 needs like using more than 1 database connections for the same class, see
64 L<DBIx::Class::Schema>.
66 =head2 Using L<DBIx::Class::Loader>.
68 This is an additional class, and not part of the DBIx::Class distribution.
69 Like L<Class::DBI::Loader>, it inspects your database, and automatically
70 creates classes for all the tables in your database. Here's a simple setup:
74 use DBIx::Class::Loader;
76 my $loader=DBIx::Class::Loader->new(
77 dsn => 'dbi:SQLite:/home/me/myapp/my.db',
78 namespace => 'MyApp::DB');
81 This should be equivalent to the manual in the section above.
82 L<DBIx::Class::Loader> takes lots of other options. For more information,
83 consult the reference documentation.
87 Once you've defined the basic classes, you can start interacting with your
88 database. The simplest way to get a column is by primary key:
90 my $frob=MyApp::DB::Frob->find(14);
92 This will run a select with id=14 in the WHERE clause, and return an instance
93 of MyApp::DB::Frob that represents this row. Once you have that row, you can
94 access and update columns
99 or if you prefer, you can use the set_column/get_column accessors instead
100 of the autogenerated accessors based on your column names.
102 Just like with L<Class::DBI>, you do an 'update' to commit your changes
107 If needed, you can drop your local changes instead like this:
109 $frob->discard_changes if $frob->is_changed;
111 As you can see, is_changed allows you to check if there are local changes to
114 =head2 Adding and removing rows.
116 To make a new row, and put it into the database, you can use the 'create'
117 method from L<DBIx::Class::Row>
119 my $new_thingie=MyApp::DB::Frob->create({
123 likewise, you can remove if from the database like this:
125 $new_thingie->delete();
127 or even without retrieving first. This operation takes the same kind of
128 arguments as a search.
130 MyApp::DB::Frob->delete({foo=>'bart'});
132 =head2 Finding your objects.
134 DBIx::Class provides a few different ways to retrieve data from your database.
135 The simplest looks something like this:
137 $rs=MyApp::DB::Frob->search(foo=>'bart');
139 note that all the search methods return a recordset in scalar context or
140 a list containing all the elements in list context.
142 We also provide a handy shortcut for doing a like search:
144 $rs=MyApp::DB::Frob->search_like(foo=>'bar%');
146 Or you can provide your own handmade WHERE clause, like
148 $rs=MyApp::DB::Frob->search_literal('foo=?','bart');
150 The other way to provide more complex queries, is to provide a
151 L<SQL::Abstract> construct to search:
153 $rs=MyApp::DB::Frob->search({
156 id => [1,14,15,65,43]
159 The search can also be modifyed by passing another hash with attributes:
161 $rs=MyApp::DB::Frob->search( {foo=>'bart'},
162 { page=>1, rows=>2, order_by=>'bar' } );
164 For a complete overview over the available attributes, see
165 L<DBIx::Class::ResultSet>