Java Programming with Oracle JDBC

Chapter 16. Strongly Typed Object SQL

Strongly typed object SQL refers to the use of client-side custom Java classes to manipulate database-side SQL objects. The classes themselves are referred to as custom because a Java class is created to mirror its database counterpart. To mirror database objects you can use one of two approaches: the JDBC API’s standard SQLData interface or Oracle’s CustomDatum interface. With the SQLData interface, a database object is represented as a custom Java class that implements the SQLData interface; however, a collection is still represented by an Array object, and a reference is still represented by a Ref object. With the Oracle CustomDatum interface, a database object is represented as an Oracle custom class file that implements the CustomDatum and CustomDatumFactory interfaces. Unlike the SQLData interface, The CustomDatum interface supports all database object types, including references and collections.

For example, in Chapter 15 we used a Struct object to manipulate a database object, an Array object for collections, and a Ref object to hold a database reference. With strongly typed object SQL, you’ll use a custom Java class to manipulate a database object, an Array object or another custom Java class for a collection, and a Ref object or yet another custom Java class to hold a database reference.

If you’re concerned with portability, then you should use the SQLData interface. Otherwise, since the SQLData interface currently doesn’t provide ...