X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?a=blobdiff_plain;f=lib%2FDBIx%2FClass%2FManual%2FIntro.pod;h=5414e0864b57de9b5c3d2374e90dea9a8af4f97b;hb=48580715af3072905f2c71dc27e7f70f21a11338;hp=4bd95d5f9a34a7f22a0079d57a814226090bd1eb;hpb=2f0790c43209011e3524dd6edc2aa3fc9913ef76;p=dbsrgits%2FDBIx-Class.git diff --git a/lib/DBIx/Class/Manual/Intro.pod b/lib/DBIx/Class/Manual/Intro.pod index 4bd95d5..5414e08 100644 --- a/lib/DBIx/Class/Manual/Intro.pod +++ b/lib/DBIx/Class/Manual/Intro.pod @@ -11,7 +11,7 @@ better way? You've come to the right place. =head1 THE DBIx::Class WAY Here are a few simple tips that will help you get your bearings with -DBIx::Class. +DBIx::Class. =head2 Tables become Result classes @@ -29,7 +29,7 @@ besides) The important thing to understand: =head2 It's all about the ResultSet So, we've got some ResultSources defined. Now, we want to actually use those -definitions to help us translate the queries we need into handy perl objects! +definitions to help us translate the queries we need into handy perl objects! Let's say we defined a ResultSource for an "album" table with three columns: "albumid", "artist", and "title". Any time we want to query this table, we'll @@ -39,18 +39,18 @@ results of: SELECT albumid, artist, title FROM album; Would be retrieved by creating a ResultSet object from the album table's -ResultSource, likely by using the "search" method. +ResultSource, likely by using the "search" method. DBIx::Class doesn't limit you to creating only simple ResultSets -- if you wanted to do something like: SELECT title FROM album GROUP BY title; -You could easily achieve it. +You could easily achieve it. -The important thing to understand: +The important thing to understand: - Any time you would reach for a SQL query in DBI, you are + Any time you would reach for a SQL query in DBI, you are creating a DBIx::Class::ResultSet. =head2 Search is like "prepare" @@ -86,40 +86,33 @@ L: 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 /); +will define later, using the load_namespaces() method: -Or load classes by namespace: + # load My::Schema::Result::* and their resultset classes + __PACKAGE__->load_namespaces(); - # load My::Schema::Album, My::Schema::Artist and My::OtherSchema::LinerNotes - __PACKAGE__->load_classes( - { - 'My::Schema' => [qw/ Album Artist /], - 'My::OtherSchema' => [qw/ LinerNotes /] - } - ); +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 call. -Or let your schema class load all classes in its namespace automatically: - - # load My::Schema::* - __PACKAGE__->load_classes(); +It is also possible to do the same things manually by calling +C 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; - use base qw/DBIx::Class/; - -Load any components required by each class with the load_components() method. -This should consist of "Core" plus any additional components you want to use. -For example, if you want serial/auto-incrementing primary keys: + package My::Schema::Result::Album; + use base qw/DBIx::Class::Core/; - __PACKAGE__->load_components(qw/ PK::Auto Core /); +Load any additional components you may need with the load_components() method, +and provide component configuration if required. For example, if you want +automatic row ordering: -C is supported for many databases; see L -for more information. + __PACKAGE__->load_components(qw/ Ordered /); + __PACKAGE__->position_column('rank'); Set the table for your class: @@ -127,7 +120,7 @@ Set the table for your class: Add columns to your class: - __PACKAGE__->add_columns(qw/ albumid artist title /); + __PACKAGE__->add_columns(qw/ albumid artist title rank /); Each column can also be set up with its own accessor, data_type and other pieces of information that it may be useful to have -- just pass C a hash: @@ -147,24 +140,31 @@ of information that it may be useful to have -- just pass C a hash: is_auto_increment => 0, default_value => '', }, - title => + title => { data_type => 'varchar', size => 256, is_nullable => 0, is_auto_increment => 0, default_value => '', + }, + rank => + { data_type => 'integer', + size => 16, + is_nullable => 0, + is_auto_increment => 0, + default_value => '', } ); DBIx::Class doesn't directly use most of this data yet, but various related modules such as L make use of it. Also it allows you to create your database tables from your Schema, instead of the other way around. -See L for details. +See L for details. See L 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. @@ -181,7 +181,8 @@ to describe a column which contains an ID of another Table, or C to make a predefined accessor for fetching objects that contain this Table's foreign key: - __PACKAGE__->has_many('albums', 'My::Schema::Artist', 'album_id'); + # in My::Schema::Result::Artist + __PACKAGE__->has_many('albums', 'My::Schema::Result::Album', 'artist'); See L for more information about the various types of available relationships and how you can design your own. @@ -207,8 +208,12 @@ many options. =head2 Connecting -To connect to your Schema, you need to provide the connection details. The -arguments are the same as for L: +To connect to your Schema, you need to provide the connection details or a +database handle. + +=head3 Via connection details + +The arguments are the same as for L: my $schema = My::Schema->connect('dbi:SQLite:/home/me/myapp/my.db'); @@ -220,7 +225,7 @@ second database you want to access: Note that L does not cache connections for you. If you use multiple connections, you need to do this manually. -To execute some sql statements on every connect you can add them as an option in +To execute some SQL statements on every connect you can add them as an option in a special fifth argument to connect: my $another_schema = My::Schema->connect( @@ -234,6 +239,16 @@ a special fifth argument to connect: See L for more information about this and other special C-time options. +=head3 Via a database handle + +The supplied coderef is expected to return a single connected database handle +(e.g. a L C<$dbh>) + + my $schema = My::Schema->connect ( + sub { Some::DBH::Factory->connect }, + \%extra_attrs, + ); + =head2 Basic usage Once you've defined the basic classes, either manually or using @@ -248,7 +263,7 @@ The simplest way to get a record is by primary key: my $album = $schema->resultset('Album')->find(14); This will run a C