title: order by in sql after subtracting column values
body: <p>i've a sql table with 3 columns: <strong>id</strong>, <strong>start</strong>, <strong>end</strong></p>
  
  <p>i've to select all(SELECT *) the results and arrange them descending from the (<strong>start-end</strong>) value..</p>
  
  <p>can i do that in a single sql command?
  any help?</p>