Persistence::Relationship::ManyToMany - Many to many relationship

 Persistence::Relationship
    |
    +----Persistence::Relationship::ManyToMany

    use Persistence::Relationship::ManyToMany ':all';

#.... entities definition

    my $entity_manager = Persistence::Entity::Manager->new(name => 'my_manager', connection_name => 'test');

    my $emp_project_entity = Persistence::Entity->new(
        name    => 'emp_project',
        alias   => 'ep',
        primary_key => ['projno', 'empno'],
        columns => [
            sql_column(name => 'projno'),
            sql_column(name => 'empno'),
            sql_column(name => 'leader'),
        ],
    );

    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'),
        ],
        value_generators => {empno => 'emp_gen'}, 
        to_many_relationships => [
            sql_relationship(target_entity => $emp_project_entity,
            join_columns => ['empno'], order_by => 'empno, projno')
        ]
    );

    my $project_entity = Persistence::Entity->new(
        name    => 'project',
        alias   => 'pr',
        primary_key => ['projno'],
        columns => [
            sql_column(name => 'projno'),
            sql_column(name => 'name', unique => 1),
        ],
        value_generators => {projno => 'project_gen'},
        to_many_relationships => [
            sql_relationship(target_entity => $emp_project_entity,
            join_columns => ['projno'], order_by => 'projno, empno')
        ]
    );

    $entity_manager->add_entities($emp_project_entity, $emp_entity, $project_entity);

    # object mapping

    package Project;

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

    entity 'project';
    column projno => has('$.id');
    column name => has('$.name');

    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';

    many_to_many 'project' => (
        attribute        => has('%.projects' => (associated_class => 'Project'), index_by => 'name'),
        join_entity_name => 'emp_project',
        fetch_method     => LAZY,
        cascade          => ALL,
    );

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

many_to_many by ':all' tag.

join_entity_name

Join entity name.

many_to_many

deserialise_attribute

Deserialises relation attribute

insert

Inserts relationship data.

merge

Merges relationship data.

delete

Deletes many to many association.

_associate_relationship_data

Persistence::Relationship Persistence::Entity Persistence::Entity::Manager Persistence::ORM

The Persistence::ManyToManyRelationship 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.

Adrian Witas, adrian@webapp.strefa.pl