How to display db results in order ?



I have a php page that is getting some data from a db, and displaying
it on a page. the only thing is it is not in order. I want the newest
entry to show up at top and the older to go down.

There is no date field in the db.

Right now I am using:
SELECT * FROM MYDB;

And everything is coming out in any old order..

Thanks.
.