NAME Data::Mapper - An implementation of Data Mapper Pattern described in PofEAA SYNOPSIS use Data::Mapper; use Data::Mapper::Adapter::DBI; my $dbh = DBI->connect($dsn, $username, $password, ...); my $adapter = Data::Mapper::Adapter::DBI->new({ driver => $dbh }); my $mapper = Data::Mapper->new({ adapter => $adapter }); # Create my $data = $mapper->create(user => { name => 'kentaro', age => 34 }); # Retrieve just one item $data = $mapper->find(user => { name => 'kentaro' }); $data->param('name'); #=> kentaro $data->param('age'); #=> kentaro # Search with some conditions $result = $mapper->search(user => { age => 34 }, { order_by => 'id DESC' }); for my $data (@$result) { $data->param('name'); ... } # Update $data->param(age => 35); my $sth = $mapper->update($data); $sth->rows; #=> 1 # Destroy my $sth = $mapper->delete($data); $sth->rows; #=> 1 WARNING This software is under the heavy development and considered ALPHA quality now. Things might be broken, not all features have been implemented, and APIs will be likely to change. YOU HAVE BEEN WARNED. DESCRIPTION Data::Mapper is an implementation of Data Mapper Pattern described in PofEAA, written by Martin Fowler, and is kind of a ORM, but not limited only to it, that is, this module just relates some data to another; for example, data from a database to Perl's objects. Data::Mapper Convention This module, actually, merely defines a simple convention how to make relations between some data to another, and now has only one adapter implementation: Data::Mapper::Adapter::DBI. Mapper *Mapper* makes relations between data from a datasource, which is typically a database, to Perl's objects, and vice versa, while keeping them independent each other, and the mapper itself. You can use Data::Mapper directly or make your own mapper by inheriting it. *Mapper* provides the methods below: * create( *$name* => *\%values* ) Creates a new data, and returns it as a *Data* object described later. * find( *$name* => *\%conditions* [, *\%options*] ) Searches data according to "\%conditions" and "\%options", and returns the first one as a *Data* object described later. * search( *$name*, *\%conditions* [, *\%options*] ) Searches data according to "\%conditions" and "\%options", and returns the all of them as an ArrayRef which contains each records as a *Data* object described later. * update( *$data* ) Updates $data in the datasource. * delete( *$data* ) Deletes the $data from the datasource. Adapter *Adapter* does CRUD operations against a datasource (database, memcached, etc.). It must implement some methods according to the convention. *Adapter* must implements the methods below: * create( *$name*, *\%values* ) Creates a new data, and returns it as a specific form described later. * find( *$name*, *\%conditions* [, *\%options*] ) Searches data according to "\%conditions" and "\%options", and returns the first one as a specific form described later. * search( *$name*, *\%conditions* [, *\%options*] ) Searches data according to "\%conditions" and "\%options", and returns the all of them as an ArrayRef which contains each records as the specific form same as the one "find()" method returns. * update( *$name*, *\%values* [, *\%conditions*] ) Updates data in a datasource according to "\%values", and "\%conditions". * delete( *$name*, *\%conditions* ) Deletes the data specified by "\%conditions" from a datasource. The return value of "create()", "find()", "search()" is either a HashRef or an object which has "as_serializable()" method to return its contents as a HashRef. You can adapt any data-retrieving module to Data::Model convention if only you implement the methods described above. Data *Data* represents a data model where you can define some business logic. You must notice that *Data* layer has no idea about what *Mapper* and *Adapter* are. It just hold the data passed by *Mapper* *Mapper* returns some instance whose class inherits *Data::Mapper::Data* object. package My::Mapper::Data::User; use parent qw(Data::Mapper::Data); package My::Mapper; use parent qw(Data::Mapper); package main; My::Mapper; my $mapper = My::Mapper->new(...); $mapper->find(user => ...) #=> Now returns data as a My::Mapper::Data::User AUTHOR Kentaro Kuribayashi SEE ALSO * Data Mapper Pattern * DBIx::ObjectMapper An existing Perl implementation of the pattern above. You might want to consult it if you want much more ORM-ish features. LICENSE Copyright (C) Kentaro Kuribayashi This library is free software; you can redistribute it and/or modify it under the same terms as Perl itself.