NAME

Persistence::Relationship::ToOne - To one relationship

CLASS HIERARCHY

 Persistence::Relationship
    |
    +----Persistence::Relationship::ToOne

SYNOPSIS

    use Persistence::Relationship::ToOne ':all';

    #entity defintion
    my $entity_manager = Persistence::Entity::Manager->new(name => 'my_manager', connection_name => 'test');
    my $emp_entity = Persistence::Entity->new(
        name    => 'emp',
        alias   => 'ep',
        primary_key => ['empno'],
        columns => [
            sql_column(name => 'empno'),
            sql_column(name => 'ename', unique => 1),
            sql_column(name => 'job'),
            sql_column(name => 'deptno'),
        ],
    );

    my $dept_entity = Persistence::Entity->new(
        name    => 'dept',
        alias   => 'dt',
        primary_key => ['deptno'],
        columns => [
            sql_column(name => 'deptno'),
            sql_column(name => 'dname'),
            sql_column(name => 'loc')
        ],
    );

    $dept_entity->add_to_many_relationships(sql_relationship(target_entity => $emp_entity, join_columns => ['deptno'], order_by => 'deptno, empno'));
    $entity_manager->add_entities($dept_entity, $emp_entity);

    #object mapping

    package Employee;

    use Abstract::Meta::Class ':all';
    use Persistence::Entity ':all';
    use Persistence::ORM ':all';

    entity 'emp';
    column empno=> has('$.id');
    column ename => has('$.name');
    column job => has '$.job';
    to_one 'dept' => (
        attribute        =>  has ('$.dept', associated_class => 'Department'),
        cascade          => ALL,
        fetch_method     => EAGER,
    );

    package Department;

    use Abstract::Meta::Class ':all';
    use Persistence::Entity ':all';
    use Persistence::ORM ':all';

    entity 'dept';
    column deptno => has('$.id');
    column dname => has('$.name');
    column loc   => has('$.location');

DESCRIPTION

Represents to one relationship. Supports eager, lazy fetch, cascading operation (inert/update/delete).

EXPORT

to_one method by ':all' tag.

METHODS

to_one

Create a new instance of to one relation. Takes associated entity's id as parameters and list of named parameters for Persistence::Relationship::OneToMany constructor.

    one_to_many 'wsus_user_service' => (
        attribute    => has('@.membership' => (associated_class => 'Membership')),
        fetch_method => EAGER,
        cascade      => ALL,
    );

deserialise_attribute

Deserialises relation attribute

insert

Inserts relationship data.

merge

Merges relationship data. #what if lazy

delete

Merges relationship data.

COPYRIGHT AND LICENSE

The Persistence::Relationship::ToOne module is free software. You may distribute under the terms of either the GNU General Public License or the Artistic License, as specified in the Perl README file.

AUTHOR

Adrian Witas, <adrian@webapp.strefa.pl</gt>

CPAN RT