title: How to find time duration of ride given its starting time and ending time by using sql query
body: <p><img src="https://i.stack.imgur.com/uJwiF.png" alt="carpooling schema" /></p>
  <p>The start_on column in RIDE table is starting date and time for each ride and ends_on column is ending date and time of ride.
  i have to fetch the ride whose travel duration is maximum i.e. [start_on - ends_on] is maximum for which ride.
  the datediff function is not working in oracle platform.
  please help with code that run on oracle.</p>