title: top 10 rows in oracle
body: <p>i have 2 tables .
  abc(CID(pk), cname,)
  order(order_id(pk), CID(fk), number_of_rentals)</p>
  
  <p>i want to fetch top 10 customers based on number of rentals.   </p>
  
  <pre><code>SELECT  cid, sum(no_rentals) as sum 
  FROM orders 
  group by cid, no_rentals
  order by no_rentals desc;
  </code></pre>
  
  <p>how can i use rownum function in above query to fetch the desired output</p>