Database programming

G'day /prog/

I'm writing a java application with a mysql db backend (indeed, performance is not what I'm after), but I'm struggling a bit. How does one go about saving data? Do you execute an update query whenever a class representing a table is changed, or would there be an interval? Or am I going about this entirely wrong?
Your advice will be greatly appreciated.

>>21
I'm not 'afraid' to write queries myself, it's just that it tends to make a huge mess of the code. Really all I'm asking is some advice as to how I should read/write from/to the database without making my code look like a terrible mess.