emp.create(db.DATA);
emp.setValue(db.DATA.DATA, new byte[]{1,2,3});
emp.update(conn);
// read a value
DBCommand cmd = db.createCommand();
cmd.select(db.DATA.DATA);
DBReader reader = new DBReader();
reader.open(cmd, conn);
while(reader.moveNext()){
byte[] value = (byte[]) reader.getValue(db.DATA.DATA);