title: Preventing duplicate entries in mySQL database with PHP
body: <p>I have a contact form that submits all fields into a mySQL database, everything is working fine with that. I want it to however, throw the sender an error message if the e-mail address field has already been submitted. (And of course not submit the data).</p>
  
  <p>What's the easiest most painless way to do this?</p>
  
  <p>My database's name is wordpress</p>
  
  <p>The table's name is wpcf7dbplugin_submits</p>