Configuring Reference Descriptor

In relational mappings that extend oracle.toplink.mappings.ForeignReferenceMapping, attributes reference other TopLink descriptors–not the data source. You can select any descriptor in the project.

Table 37-6 summarizes which relational mappings support this option.

Table 37-6 Relational Mapping Support for Reference Descriptor

Mapping	Using TopLink Workbench	Using Java
One-to-One Mapping
Variable One-to-One Mapping
One-to-Many Mapping
Many-to-Many Mapping
Aggregate Collection Mapping
Aggregate Object Mapping

Using TopLink Workbench

To specify a reference descriptor for a relational mapping, use this procedure.

1. Select the mapped attribute in the Navigator. Its properties appear in the Editor.

2. Click the General tab. The General tab appears.

   Figure 37-2 General Tab, Reference Descriptor Field

   
   Description of "Figure 37-2 General Tab, Reference Descriptor Field"
   
   

Use the Reference Descriptor field to select the descriptor referenced by this relationship mapping.

Note: For aggregate mappings the Reference Descriptor must be an aggregate. See "Configuring a Relational Descriptor as a Class or Aggregate Type" for more information. For variable one-to-one mappings, the Reference Descriptor must be an interface. See Chapter 41, "Configuring a Relational Variable One-to-One Mapping" for more information.

You can specify a reference descriptor that is not in the current TopLink Workbench project. For example, to create a mapping to an Employee class that does not exist in the current project, do the following:

1. Add the Employee class to your current project. See "Working With Projects".

2. Create the relationship mapping to the Employee descriptor.

3. Deactivate the Employee descriptor. See "Active and Inactive Descriptors".

When you generate the deployment XML for your project, the mapping to the Employee class will be included, but not the Employee class.