Here are a few simple tips that will help you get your bearings with
DBIx::Class.
-=head2 Tables become ResultSources
+=head2 Tables become Result classes
-DBIx::Class needs to know what your Table structure looks like. You do that by
-defining L<DBIx::Class::ResultSource>s. Each table gets a ResultSource, which
-defines the Columns it has, along with any Relationships it has to other tables.
-(And oh, so much more besides) The important thing to understand:
+DBIx::Class needs to know what your Table structure looks like. You
+do that by defining Result classes. Result classes are defined by
+calling methods proxied to L<DBIx::Class::ResultSource>. Each Result
+class defines one Table, which defines the Columns it has, along with
+any Relationships it has to other tables. (And oh, so much more
+besides) The important thing to understand:
- A ResultSource == Table
+ A Result class == Table
(most of the time, but just bear with my simplification)
Setting up a ResultSet does not execute the query; retrieving
the data does.
+=head2 Search results are returned as Rows
+
+Rows of the search from the database are blessed into
+L<DBIx::Class::Row> objects.
+
=head1 SETTING UP DBIx::Class
Let's look at how you can set and use your first native L<DBIx::Class> tree.
use base qw/DBIx::Class::Schema/;
In this class you load your result_source ("table", "model") classes, which we
-will define later, using the load_classes() method. You can specify which
-classes to load manually:
-
- # load My::Schema::Album and My::Schema::Artist
- __PACKAGE__->load_classes(qw/ Album Artist /);
-
-Or load classes by namespace:
+will define later, using the load_namespaces() method:
- # load My::Schema::Album, My::Schema::Artist and My::OtherSchema::LinerNotes
- __PACKAGE__->load_classes(
- {
- 'My::Schema' => [qw/ Album Artist /],
- 'My::OtherSchema' => [qw/ LinerNotes /]
- }
- );
+ # load My::Schema::Result::* and their resultset classes
+ __PACKAGE__->load_namespaces();
-Or let your schema class load all classes in its namespace automatically:
+By default this loads all the Result (Row) classes in the
+My::Schema::Result:: namespace, and also any resultset classes in the
+My::Schema::ResultSet:: namespace (if missing, the resultsets are
+defaulted to be DBIx::Class::ResultSet objects). You can change the
+result and resultset namespaces by using options to the
+L<DBIx::Class::Schema/load_namespaces> call.
- # load My::Schema::*
- __PACKAGE__->load_classes();
+It is also possible to do the same things manually by calling
+C<load_classes> for the Row classes and defining in those classes any
+required resultset classes.
Next, create each of the classes you want to load as specified above:
- package My::Schema::Album;
+ package My::Schema::Result::Album;
use base qw/DBIx::Class/;
Load any components required by each class with the load_components() method.
See L<DBIx::Class::ResultSource> for more details of the possible column
attributes.
-Accessors are created for each column automatically, so My::Schema::Album will
+Accessors are created for each column automatically, so My::Schema::Result::Album will
have albumid() (or album(), when using the accessor), artist() and title()
methods.
make a predefined accessor for fetching objects that contain this Table's
foreign key:
- __PACKAGE__->has_many('albums', 'My::Schema::Artist', 'album_id');
+ __PACKAGE__->has_many('albums', 'My::Schema::Result::Artist', 'album_id');
See L<DBIx::Class::Relationship> for more information about the various types of
available relationships and how you can design your own.
my $album = $schema->resultset('Album')->find(14);
This will run a C<SELECT> with C<albumid = 14> in the C<WHERE> clause, and
-return an instance of C<My::Schema::Album> that represents this row. Once you
+return an instance of C<My::Schema::Result::Album> that represents this row. Once you
have that row, you can access and update columns:
$album->title('Physical Graffiti');
=head2 Adding and removing rows
To create a new record in the database, you can use the C<create> method. It
-returns an instance of C<My::Schema::Album> that can be used to access the data
+returns an instance of C<My::Schema::Result::Album> that can be used to access the data
in the new record:
my $new_album = $schema->resultset('Album')->create({
For a complete overview of the available attributes, see
L<DBIx::Class::ResultSet/ATTRIBUTES>.
+=head1 NOTES
+
+=head2 Problems on RHEL5/CentOS5
+
+There used to be an issue with the system perl on Red Hat Enterprise
+Linux 5, some versions of Fedora and derived systems. Further
+information on this can be found in L<DBIx::Class::Manual::Troubleshooting>
+
=head1 SEE ALSO
=over 4