=item .. create a database to use?
-First, choose a database. For testing/experimenting, we reccommend
+First, choose a database. For testing/experimenting, we recommend
L<DBD::SQLite>, which is a self-contained small database (i.e. all you
need to do is to install L<DBD::SQLite> from CPAN, and it works).
the tables are to be joined. The condition may contain as many fields
as you like. See L<DBIx::Class::Relationship::Base>.
-=item .. define a relationship across an intermediate table? (many-to-many)
+=item .. define a relationship bridge across an intermediate table? (many-to-many)
-Read the documentation on L<DBIx::Class::Relationship/many_to_many>.
+The term 'relationship' is used loosely with many_to_many as it is not considered a
+relationship in the fullest sense. For more info, read the documentation on L<DBIx::Class::Relationship/many_to_many>.
=item .. stop DBIx::Class from attempting to cascade deletes on my has_many and might_have relationships?
=item .. search with an SQL function on the left hand side?
-To use an SQL function on the left hand side of a comparison:
+To use an SQL function on the left hand side of a comparison you currently need
+to resort to literal SQL:
- ->search({ -nest => \[ 'YEAR(date_of_birth) = ?', [ plain_value => 1979 ] ] });
+ ->search( \[ 'YEAR(date_of_birth) = ?', [ plain_value => 1979 ] ] );
Note: the C<plain_value> string in the C<< [ plain_value => 1979 ] >> part
should be either the same as the name of the column (do this if the type of the
-return value of the function is the same as the type of the column) or
-otherwise it's essentially a dummy string currently (use C<plain_value> as a
-habit). It is used by L<DBIx::Class> to handle special column types.
-
-Or, if you have quoting off:
-
- ->search({ 'YEAR(date_of_birth)' => 1979 });
+return value of the function is the same as the type of the column) or in the
+case of a function it's currently treated as a dummy string (it is a good idea
+to use C<plain_value> or something similar to convey intent). The value is
+currently only significant when handling special column types (BLOBs, arrays,
+etc.), but this may change in the future.
=item .. find more help on constructing searches?
L<DBIx::Class::ResultSet/order_by> attributes to order your data and
pick off a single row.
-See also L<DBIx::Class::Manual::Cookbook/Retrieve_one_and_only_one_row_from_a_resultset>.
+See also L<DBIx::Class::Manual::Cookbook/Retrieve one and only one row from a resultset>.
A less readable way is to ask a regular search to return 1 row, using
L<DBIx::Class::ResultSet/slice>:
=item .. update a column using data from another column?
To stop the column name from being quoted, you'll need to tell DBIC
-that the right hand side is an SQL identity (it will be quoted
+that the right hand side is an SQL identifier (it will be quoted
properly if you have quoting enabled):
->update({ somecolumn => { -ident => 'othercolumn' } })
=head2 Custom methods in Result classes
-You can add custom methods that do arbitrary things, even to unrelated tables.
-For example, to provide a C<< $book->foo() >> method which searches the
+You can add custom methods that do arbitrary things, even to unrelated tables.
+For example, to provide a C<< $book->foo() >> method which searches the
cd table, you'd could add this to Book.pm:
sub foo {
write your own methods, you can.
For example, to provide a C<< $book->foo() >> method to manually implement
-what create_related() from L<DBIx::Class::Relationship::Base> does, you could
+what create_related() from L<DBIx::Class::Relationship::Base> does, you could
add this to Book.pm:
sub foo {
=item How do I store my own (non-db) data in my DBIx::Class objects?
-You can add your own data accessors to your classes.
+You can add your own data accessors to your Result classes.
One method is to use the built in mk_group_accessors (via L<Class::Accessor::Grouped>)
- package MyTable;
+ package App::Schema::Result::MyTable;
- use parent 'DBIx::Class';
+ use parent 'DBIx::Class::Core';
__PACKAGE__->table('foo'); #etc
__PACKAGE__->mk_group_accessors('simple' => qw/non_column_data/); # must use simple group
An another method is to use L<Moose> with your L<DBIx::Class> package.
- package MyTable;
+ package App::Schema::Result::MyTable;
use Moose; # import Moose
use Moose::Util::TypeConstraint; # import Moose accessor type constraints
- extends 'DBIx::Class'; # Moose changes the way we define our parent (base) package
+ extends 'DBIx::Class::Core'; # Moose changes the way we define our parent (base) package
has 'non_column_data' => ( is => 'rw', isa => 'Str' ); # define a simple attribute
package Your::Schema::Group;
use Class::Method::Modifiers;
-
+
# ... declare columns ...
-
+
__PACKAGE__->has_many('group_servers', 'Your::Schema::GroupServer', 'group_id');
__PACKAGE__->many_to_many('servers', 'group_servers', 'server');
-
+
# if the server group is a "super group", then return all servers
# otherwise return only servers that belongs to the given group
around 'servers' => sub {
package Your::Schema::Group;
use Method::Signatures::Simple;
-
+
# ... declare columns ...
-
+
__PACKAGE__->has_many('group_servers', 'Your::Schema::GroupServer', 'group_id');
__PACKAGE__->many_to_many('servers', 'group_servers', 'server');
-
+
# The method keyword automatically injects the annoying my $self = shift; for you.
method servers {
return $self->result_source->schema->resultset('Server')->search({ ... });
package Your::Schema::Group;
use Sub::Name;
-
+
# ... declare columns ...
-
+
__PACKAGE__->has_many('group_servers', 'Your::Schema::GroupServer', 'group_id');
__PACKAGE__->many_to_many('servers', 'group_servers', 'server');
-
+
*servers = subname servers => sub {
my $self = shift;
return $self->result_source->schema->resultset('Server')->search({ ... });
};
-
+
=back
=head2 Notes for CDBI users
projects / dbsrgits/DBIx-Class.git / blobdiff