title: What is equivalent for @Formula(used in jpa), in webflux and r2dbc?
body: <p>I have a <code>firstName</code> and <code>lastName</code> in my database, and I wanna make a <code>fullname</code> variable,
  I used to set <code>@Formula</code> annotation in hibernate, but as I changed my services to reactive(webflux) and use <code>r2dbc</code>, I can't use it anymore!</p>
  <p>my previous code was something like this:</p>
  <pre><code>public class OperatorUser implements UserDetails {
      @Id
      @Column(name = &quot;ID&quot;)
      private Long id;
  
      @Column(name = &quot;FIRST_NAME&quot;)
      private String firstName;
  
      @Column(name = &quot;LAST_NAME&quot;)
      private String lastName;
  
      @Column(name = &quot;ADDRESS&quot;)
      private String address;
  
      @Formula(&quot;FIRST_NAME || \' \' || LAST_NAME&quot;)
      private String fullname; 
  </code></pre>