Skip Headers

# Building Relational Projects for an Object-Relational Database

Previous

Next

TopLink Workbench does not currently support relational projects for an object-relational database. You must create such a relational project in Java.

Using Java, you can create a relational project for transactional persistence of Java objects to an object-relational database that supports data types specialized for object storage (such as Oracle Database) accessed using JDBC.

When using TopLink to build a relational project for an object-relational database, consider the following:

- You must create a Java class and a TopLink `ObjectRelationalDescriptor` for each structured type (`Struct/object-type`)

- TopLink supports only arrays (`Varrays`) of basic types or arrays on structured types (`Struct/object-type`).

  TopLink does not support arrays of `Refs` or arrays of nested tables.

- TopLink supports only nested tables of `Refs`.

  TopLink does not support nested tables of basic types, structured types, or array types.

The general development process for building a relational project for an object-relational database is as follows:

1. Define structured object-types in the database.

2. Define tables of the structured object-types in the database.

3. Define the Java classes that will map to the structured object-types.

4. Create a relational project (see "Creating a Project").

5. Create an object-relational descriptor for each Java class (see "Creating an Object-Relational Descriptor").

6. Create object-relational mappings from each persistent field of each Java class to the corresponding object-types and object-type tables (see Configuring an Object-Relational Mapping).

Table: Components of a Relational Project for an Object-Relational Database describes the components of a relational project for an object-relational database.

Components of a Relational Project for an Object-Relational Database

Component | Supported Types
--- | ---

Data Source

For more information, see the following:

- "DatabaseLogin"

- "Database Platforms"

Descriptors | For more information, see "Object-Relational Descriptors".

Mappings

For more information, see the following:

- Mappings

- Object-Relational Mappings