When I was developing the chapters on JDBC - Java Database Connectivity - I wanted to include real code, real examples that people could run with a real database. I gave some careful consideration to how to do that.
I could have used Oracle as my example. It is the leading brand database, available for several platforms commercially. But it is a serious industrial-strength database that takes time and space to install. A lot of people wouldn't have it at home and it might be hard for them to get it.
I decided a freely-available open source product would be the best bet. There are several available - I list a few of the contenders in Just Java. But I worried about people who were using platforms that these databases did not have a version for. And I did a web search to see if there were other options.
To my great joy and delight, I found the McKoi database. This was an open source database, relational database with full support for the industry standard SQL query language, AND written in Java! Hooray! No platform problems, it runs everywhere! I immediately got in touch with the author Toby Downer. Toby is a very talented programmer with a generous nature, and devoted a lot of his time to implementing McKoi and making it available - freely available to everyone from the McKoi website at http://www.mckoi.com
Not only that, McKoi comes with source code too! So when you are interested you can start to review the code and see how a real database is implemented. Toby keeps McKoi current (a new release came out in August) and makes it available under the GPL license. I cannot say enough good things about Toby's work and generosity -- he has made it possible for a lot of people to have a GREAT learning experience with JDBC, and much more besides. I hope everyone will follow his example, and write great open source software and share it with others in the years to come.
So to learn Java and databases, you basically get the free download from McKoi.com, install it on your system by putting the jar files in your class path, and get going! (I walk through this in detail in the text).
The hardest part about learning JDBC is actually learning SQL - the database programming language used throughout the industry. SQL is a wordy, sometimes quirky language, but it is a real industry standard. McKoi comes with a free visual tool and a sample database! You can use the two together to walk through SQL and see the results immediately on your screen. This is a fabulous learning experience! The best possible way to master SQL, and I walk you through it step-by-step in Just Java chapters 23 and 24.
Author of <a href="http://www.amazon.com/exec/obidos/ASIN/0131482114/ref=jranch-20" target="_blank" rel="nofollow">Just Java(TM) 2 (6th Edition)</a>