title: Designing a helpdesk program
body: <p>I am trying to design a helpdesk program and this is my database design. Is it OK?</p>
  
  <p><a href="https://i.stack.imgur.com/c484w.jpg" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/c484w.jpg" alt="enter image description here"></a></p>
  
  <p>Also, I would like to have a net working time calculated for each ticket. Is it only possible with a query?</p>
  
  <p>Thanks. </p>