README for DataMapper

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Dominik Liebler
2013-09-24 13:11:41 +02:00
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namespace DesignPatterns\DataMapper;
/**
* DataMapper pattern
*
* Purpose:
* A Data Mapper, is a Data Access Layer that performs bidirectional transfer of
* data between a persistent data store (often a relational database) and an in
* memory data representation (the domain layer). The goal of the pattern is to
* keep the in memory representation and the persistent data store independent of
* each other and the data mapper itself. The layer is composed of one or more
* mappers (or Data Access Objects), performing the data transfer. Mapper
* implementations vary in scope. Generic mappers will handle many different domain
* entity types, dedicated mappers will handle one or a few.
* (FROM http://en.wikipedia.org/wiki/Data_mapper_pattern)
*
* The key point of this pattern is, unlike Active Record pattern, the datamodel
* follows Single Responsibility Principle.
*
* Examples:
* - DB Object Relational Mapper (ORM) : Doctrine2 uses DAO named as "EntityRepository"
*
* class UserMapper
*/
class UserMapper
{