org.assistments.service.dao.base

Interface IsLogicalDao

All Known Subinterfaces:

ActionDao, ContentPropertyDao, LegacyCertifiedFolderDao, ObjectPropertyDao

All Known Implementing Classes:

JdbcActionDao, JdbcCertifiedFolderDao, JdbcContentPropertyDao, JdbcObjectPropertyDao

public interface IsLogicalDao

The typical Data Access Object interface represents a 1:1 physical mapping to a concrete unit of persistable storage. For the SDK (at present), that concrete unit of storage is a single database table.

At the implementation level, that mapping results in a POJO domain object mapping 1:1 with the concrete unit of persistable storage. That is to say: A domain object represents a row from a single database table.

In this typical mapping, we refer to the DAO as a Physical DAO.

In some cases however, a POJO domain object encapsulates data from multiple concrete units of persistable storage. In that case, to maintain the notion of a 1:1 mapping of POJO domain object to a DAO, the implementing DAO class is considered a Logical DAO rather than a Physical DAO from above.

This IsLogicalDAO interface acts as a marker indicating the implementing DAO class represents a Logical DAO, combining the data from multiple Physical DAOs to create the appearance of a 1:1 mapping of a domain object to persistable storage.

The proper use of IsLogicalDAO should (we hope) minimize the need for implementing Manger classes to, on their own, have to be combining data from various Physical DAOs. That data should be available via Logical DAOs.