This chapter introduces options specific to an EIS descriptor.
This chapter includes the following sections:
For information on descriptor concepts and features common to more than one type of TopLink descriptors, see Chapter 16, "Introduction to Descriptors".
Using EIS descriptors in an EIS project created with TopLink Workbench, you can configure EIS mappings (see Section 77.1, "EIS Mapping Types") to XML records.
Using EIS descriptors in an EIS project that you create in Java, you can configure EIS mappings to any supported EIS record type: XML, mapped, or indexed.
See Part XXVII, "Creation and Configuration of Descriptors" for information on how to create and configure descriptors regardless of their type.
For information specific to creation and configuration of EIS descriptors, see the following:
When working with descriptors for a parent (source) and a child (target) objects, you have to accomplish the following:
if the source object exists, then you must ensure that the target object also exists;
if the source object is destroyed, then you must ensure that the target object is also destroyed.
For more information, see Section 16.2.5, "Descriptors and Aggregation".
In your EIS project, designate the descriptors for the source and target objects to reflect this relationship as Root and Composite Descriptors in EIS Projects.
In an EIS project, you can designate the descriptor as a composites (see Section 18.104.22.168, "EIS Composite Descriptors").
The type of EIS mapping you whish to create will determine whether you configure an EIS descriptor as a composite or root (see Section 77.2.6, "Composite and Reference EIS Mappings").
For more information, see Section 76.6, "Configuring an EIS Descriptor as a Root or Composite Type".
You cannot configure EJB information for an EIS descriptor designated as an composite (see Section 16.2.3, "Descriptors and CMP and BMP").
You can configure inheritance for an EIS descriptor designated as a composite (see Section 16.2.2, "Descriptors and Inheritance"), however, in this case, all the descriptors in the inheritance tree must be composites. Composite and root descriptors cannot exist in the same inheritance tree.
You can use descriptors to describe the inheritance relationships between classes in your EIS project. For more information, see the following:
For EIS projects, TopLink assumes that all of the classes in an inheritance hierarchy have the same primary key, as set in the root descriptor. Child descriptors associated with data source representations that have different primary keys must define the mapping between the root primary key and the local one.
For more information, see Section 119.2, "Configuring Primary Keys".