title: How can I ensure unique file names for images uploaded to server?
body: <p>I'm creating a web application that allows users to upload images to a server.</p>
  
  <p>How can I prevent duplicate image file names when a user uploads images?</p>
  
  <p>How can I change the filename to a unique name that is no duplicate of any previous image's name (or next image that might be uploaded)?</p>
  
  <p><strong>Editing :</strong></p>
  
  <p><strong>if i user primary key autoincrement as image filename for each images ? is it will be useful ?</strong> </p>