QSqlDatabase: QMYSQL driver not loaded
How do I load it ?
///check database driver with :
if (!QSqlDatabase::drivers().contains("QMYSQL"))
QMessageBox::critical(this, "Unable to load database", "Needs the QMYSQL driver");

If you get this error message, you probably didn't install the QMYSQL driver.
To install it have a look at the Qt Centre FAQ : Enabling MySQL support

Cheers