The Mapping Assistant (SAP Library - BC

The Mapping Assistant

Purpose

The Mapping Assistant is a component of the Class Builder that makes it possible to define where persistent object attributes are stored in a database.
A status description is stored as an entry in one or more tables in the database for each object.
The persistence service of the Object Services uses this information both when instantiating existing persistent objects and when saving their status after changes. At the end of the transaction, the persistent status part of the objects is stored as the new status description.

The Mapping Assistant is used to assign persistent classes to database tables or structures and persistent attributes to fields of these tables or structures. The persistence mapping is used to generate the dependent code passages in the class of the relevant class actor.

Prerequisites

The database tables and structures needed to map persistence already exist.

Features

Assign the persistent attributes in the Class Builder based on the type information in the database table.
The application developer only has to define which field of the database table should be mapped to which attribute of the persistent class.

Generate corresponding database access methods (GET and SET methods) for value attributes, key fields and reference attributes.

Assign GUIDs for identifying objects.

Generate auxiliary classes, the class actor class (CA class) and their superclass (CB class) for each application class (CL class). These two classes are needed for managing persistent objects using Object Services.

Partially generate in case of manual implementation of the database access layer. In this case how the object data should be stored in the database is not defined. As a result, no load and save methods are generated for the CA class.

Subsequent processing of attributes and their assignments.

See also:

Structure of the Main Screen

Creating Persistent Classes

Defining Persistence Mapping