title: Liquibase , how to add a group of fields like primary key?
body: <p>I have an entity with a group of fields in primary key.
  Like this :</p>
  
  <pre><code>@Entity
  @Table(name = "pv_object")
  @NamedQuery(name = "PreviousObject.findAll", query = "SELECT p FROM PreviousObject p")
  public class PreviousObject implements Serializable {
  
      @EmbeddedId
      private FieldsDTO fieldsdto; 
  
      //
  }
  </code></pre>
  
  <p>FieldsDTO class contains 2 String and 2 Integer.</p>
  
  <p>I have and I use Liquidbase on my project in a XML file, but, I don't know how to represent this ID of 4 fields in liquidbase.</p>
  
  <p>Thanks for your help :)  </p>