title: MySQL if a row appears twice only display it once, but if it appears n times(which cant be two) then display its name n times?
body: <p>for example:</p>
  
  <p>database:</p>
  
  <ul>
  <li>Tom</li>
  <li>David</li>
  <li>Tom</li>
  <li>George</li>
  <li>David</li>
  <li>David</li>
  </ul>
  
  <p>after the mysql command these will come out as a result:</p>
  
  <ul>
  <li>Tom</li>
  <li>David</li>
  <li>George</li>
  <li>David</li>
  <li>David</li>
  </ul>
  
  <p>thank you for your patience.</p>