NAME

Persistence::ValueGenerator::TableGenerator - Unique value generator based on database table

CLASS HIERARCHY

 Persistence::ValueGenerator
    |
    +----Persistence::ValueGenerator::TableGenerator

SYNOPSIS

   use Persistence::ValueGenerator::TableGenerator;

   my $generator = Persistence::ValueGenerator::TableGenerator->new(
        name                     => 'pk_generator',
        entity_manager_name      => $entity_manager_name,
        table                    => 'primary_key_generator',
        schema                   => '',
        primary_key_column_name  => 'pk_column',
        primary_key_column_value => 'empno',
        value_column             => 'value_column',
        allocation_size          =>  20,
    );

   my $seq = $generator->nextval;

   or 

   use Persistence::ValueGenerator::TableGenerator ':all';

   my $generator = table_generator 'pk_generator' => (
        entity_manager_name      => $entity_manager_name,
        table                    => 'primary_key_generator',
        schema                   => '',
        primary_key_column_name  => 'pk_column',
        primary_key_column_value => 'empno',
        value_column             => 'value_column',
        allocation_size          =>  20,
   );

DESCRIPTION

Represents sequence generator that uses table name The primary_key_column_name holds a value that is used to match the primary key you are generating for. The value_column holds the value of the counter.

    use Persistence::ValueGenerator::TableGenerator;
    use Persistence::Entity::Manager;

    my $entity_manager = Persistence::Entity::Manager->new(connection_name => 'my_connection');
    my $generator = Persistence::ValueGenerator::TableGenerator->new(
        entity_manager           => $entity_manager,
        name                     => 'pk_generator',
        table                    => 'seq_generator',
        schema                   => '',
        primary_key_column_name  => 'pk_column',
        primary_key_column_value => 'empno',
        value_column             => 'value_column',
        allocation_size          =>  20,
    );

   # for that instance you need the following table
   # CREATE TABLE seq_generator(pk_column VARCHAR2(30), value_column double)
   # CREATE emp(empno number, ename varchar2(100), deptno number);

EXPORT

table_generator by ':all' tag.

ATTRIBUTES

table

Table name of the generator table.

schema

Schema name of the generator table.

primary_key_column_name

Name of the column that identifies the specific table primary key you are generating for.

primary_key_column_value

Used to match up with the primary key you are generating for.

value_column

Specifies the name of the column that will hold the counter for the generated primary key.

METHODS

initialise

initialise

initailise_entity

id

returns schma.table as id

retrieve_next_value

Checks current seq number in database, increments counter by $self->allocation_size + 1

table_generator

Creates a new instance of Persistence::ValueGenerator::TableGenerator

SEE ALSO

Persistence::Entity Persistence::Entity::GeneratedValue

COPYRIGHT AND LICENSE

The Persistence::ValueGenerator::TableGenerator 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