1.1 What the JDBC 3.0 API Includes

The latest version, the JDBC 3.0 API, incorporates all previous versions and adds both new features and enhancements for existing features. One of the bigger changes is that all of the JDBC 3.0 API is included in the JavaTM 2 platform, Standard Edition (J2SETM), version 1.4, meaning that the Optional Package API no longer needs to be downloaded separately.
The JDBC 3.0 API includes the JDBC 1.0 API, which provides the basic functionality for data access. It also includes the JDBC 2.0 API, which supplements the basic API with more advanced features and provides a standard way to access the latest object-relational features being supported by today's relational database management systems. The JDBC 2.0 API also contains features such as scrollable and updatable result sets and improved performance. Further, it extends JDBC technology beyond the client to the server with connection pooling and distributed transactions. The JDBC 3.0 API adds features such as savepoints, pooled statements, and the ability to retrieve column values that are auto-generated keys, to name but a few. Appendix A has a complete list of new features for the 2.0 and 3.0 APIs.
The following list defines various terms used in talking about the JDBC API.

• JDBC 3.0 API - the complete JDBC API, including both the java.sql package and the javax.sql package.
• JDBC 2.1 core API - the JDBC API that is part of the Java 2 SDK, Standard Edition, version 1.2, which includes the JDBC 1.0 API . Some of the features added in this version are scrollable result sets, batch updates, programmatic updates, and support for the SQL99 data types.
• JDBC Optional Package API - the package javax.sql, which makes it easier to build server-side applications using the Java platform. This package provides an open architecture that supports connection pooling and distributed transactions that span multiple database servers. The DataSource API plays an integral part in these capabilities and also works with the JavaTM Naming and Directory InterfaceTM (JNDI) to improve portability and make code maintenance easier. The javax.sql package also provides the RowSet API, which makes it easy to handle data sets from virtually any data source as JavaBeansTM components.
• java.sql package - the JDBC 1.0 API, plus the JDBC 2.1 core API, plus some of the new API in the JDBC 3.0 API
• javax.sql package - see JDBC Optional Package API
In keeping with the policy of maintaining backward compatibility, applications written using the JDBC 1.0 API will continue to run with both the Java 2 SDK, Standard Edition, and the Java 2 SDK, Enterprise Edition, just as they have always run. Having been well designed from the beginning, the JDBC 1.0 API is essentially unchanged. Applications using features added in later versions will, of course, need to be run using a driver that supports those features.