Book excerpt: JDBC is the key Java technology for relational database access. Oracle is arguably the most widely used relational database platform in the world. In this book, Donald Bales brings these two technologies together, and shows you how to leverage the full power of Oracle's implementation of JDBC. You begin by learning the all-important mysteries of establishing database connections. This can be one of the most frustrating areas for programmers new to JDBC, and Donald covers it well with detailed information and examples showing how to make database connections from applications, applets, Servlets, and even from Java programs running within the database itself. Next comes thorough coverage of JDBC's relational SQL features. You'll learn how to issue SQL statements and get results back from the database, how to read and write data from large, streaming data types such as BLOBs, CLOBs, and BFILEs, and you'll learn how to interface with Oracle's other built-in programming language, PL/SQL. If you're taking advantage of the Oracle's relatively new ability to create object tables and column objects based on user-defined datatypes, you'll be pleased with Don's thorough treatment of this subject. Don shows you how to use JPublisher and JDBC to work seamlessly with Oracle database objects from within Java programs. You'll also learn how to access nested tables and arrays using JDBC. Donald concludes the book with a discussion of transaction management, locking, concurrency, and performance--topics that every professional JDBC programmer must be familiar with. If you write Java programs to run against an Oracle database, this book is a must-have.