title: Unique text field in MySQL and php
body: <p>I've created a salt using; md5(rand(0,10000000)); (there is probably a better way?)</p>
  
  <p>There doesn't seem to be possible to make a text field unique in MYSQL. So how do I check if the salt has already been used for a previous user?</p>
  
  <p>Or should I generate the salt based on the current date/time? as it is impossible for 2 users to register at exactly the same time correct?</p>