Is it possible to save information from a JAVA applet to a MySql database? I do not think this is possible since from my limited JAVA knowledge the applet is on the users machine not on the server. But I guess I will find out.
Taking a course in JAVA and want to get a head start on a project I have been thinking of.
As a general statement, no, you wouldn't be able to do this. The default applet security model only allows socket connections back to the same host that served it.
One way you could do this is to do an HTTP POST back to something on the server that is setup to handle it (i.e. Servlet, PHP script, etc.)
Applets do not allow you to write a local file either (again, by default) so your only real option for persisting applet data is to write it back to the server somehow. The advantage of the HTTP POST method is that a web page can be written to do the same thing at some point and the backend doesn't care which client it is communicating with.
That is totally different. With a JDBC driver it is very easy for a Java application to store data in a local or remote MySQL (or indeed any vendor) database. I'd read up on JDBC. If you've ever done ODBC programming (and, shudder, I've done more than my share) then you'll get the concepts of JDBC quickly. Even if you haven't JDBC isn't very difficult.
I can post a quick JDBC program if you need an example.
Local applet or command line application can connect using the JDBC driver. This is the basic way of accessing a database. There's many other variations that build on top of this (RowSets, EJB, Hibernate). Most simple apps would just do a few JDBC calls though.
If you are doing a remote applet, the accepted way to do so would be to connect the applet to a J2EE servlet application over IIOP or HTTP. The applet talks to the server and the server is responsible for the database operations.
One thing to note about the HyperSonic SQL database is that it won't be nearly as scalable as the MySQL database. If your application does not require large amounts of data or concurrent connections, HSQL would be a much more light-weight choice to use.