31 Configuring a Relational One-to-One Mapping

This chapter describes the various components that you must configure in order to use a relational one-to-one mapping.

This chapter includes the following sections:

• Introduction to Relational One-to-One Mapping Configuration

For information on how to configure TopLink mappings options common to two or more mapping types, see Chapter 121, "Configuring a Mapping".

For information on how to create TopLink mappings, see Chapter 120, "Creating a Mapping".

Table 31-1 lists the configurable options for a relational one-to-one mapping.

31.1 Introduction to Relational One-to-One Mapping Configuration

Table 31-1 lists the configurable options for a relational one-to-one mapping.

Table 31-1 Configurable Options for Relational One-to-One Mapping

Option to Configure	Oracle JDeveloper	TopLink Workbench	Java
Reference descriptor (see Section 28.4, "Configuring Reference Descriptor")
Method or direct field access (see Section 121.6, "Configuring Method or Direct Field Accessing at the Mapping Level")
Read-only mapping (see Section 121.2, "Configuring Read-Only Mappings")
Private or Independent relationships (see Section 121.7, "Configuring Private or Independent Relationships")
Batch reading (see Section 28.5, "Configuring Batch Reading")
Joining (see Section 28.8, "Configuring Joining at the Mapping Level")
Indirection (lazy loading) (see Section 121.3, "Configuring Indirection (Lazy Loading)")
Bidirectional relationship (see Section 121.18, "Configuring Bidirectional Relationship")
Mapping comments (see Section 121.8, "Configuring Mapping Comments")
Table and field references (see Section 28.7, "Configuring Table and Field References (Foreign and Target Foreign Keys)")

Example 31-1 shows how to create a one-to-one mapping and add it to a descriptor using Java code.

Example 31-1 One-to-One Mapping

public void customize(ClassDescriptor descriptor) { 
    OneToOneMapping mapping = new OneToOneMapping();  

    // configure mapping
    ...   

    // add mapping to descriptor
    descriptor.addMapping(mapping);
}

For more information, see the following:

• Section 27.5, "One-to-One Mapping"

• Chapter 28, "Configuring a Relational Mapping"

• Part XXVIII, "Creation and Configuration of Mappings"

For information on using JPA to configure one-to-one mappings, see "@OneToOne" section of EclipseLink Developer's Guide at http://wiki.eclipse.org/Introduction_to_EclipseLink_JPA_%28ELUG%29#.40OneToOne.