This week's book giveaway is in the General Computing forum. We're giving away four copies of Arduino in Action and have Martin Evans, Joshua Noble, and Jordan Hochenbaum on-line! See this thread for details.
They're completely different, unrelated products. Their similarities are that they're relational database that implement SQL, and that JDBC drivers are available for both. Their full feature lists can be found on their respective web sites.
They are two different DBs.
java DB must be based on java,it is Sun's database.
mysql can be used for many languages, such as C、C++、Eiffel、Java、Perl、PHP、Python、Ruby and Tcl