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.
Deserialises relation attribute
Inserts relationship data.
Merges relationship data.
Deletes many to many association.
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
To install Persistence::Entity, copy and paste the appropriate command in to your terminal.
cpanm
cpanm Persistence::Entity
CPAN shell
perl -MCPAN -e shell install Persistence::Entity
For more information on module installation, please visit the detailed CPAN module installation guide.