title: Create custom JPA query function
body: <p>I'm using EclipseLink. Is is possible to use custom query function like:</p>
  
  <blockquote>
    <p>Select u from User u where my_function(u.name) = my_function(:param)</p>
  </blockquote>
  
  <p>I would like to retrive entities based on custom created slug names rather than id (and remove any id's from url)</p>