title: Can't control the view function
body: <p>I am having a problem on my viewing function in my desktop application.
  The program lets the user view the names and corresponding details by clicking the "view all" button.
  The problem is if the user clicks the "View all" button again it will add another set of the list stored in the database.</p>
  
  <p>This is what happened after the second click</p>
  
  <p><img src="https://i.stack.imgur.com/lc5Hn.jpg" alt="enter image description here"></p>
  
  <p>Can you help me stop this problem?</p>