title: Grails GORM Inheritance changing discriminator column
body: <p>I'd like to use an Enum or String in place of column class to map on table inheritance in Grails. </p>
  
  <p>For exemple </p>
  
  <pre><code>@Entity
  @Table(name = "person")
  @Inheritance(strategy = InheritanceType.SINGLE_TABLE)
  @DiscriminatorValue("USR")
  @DiscriminatorColumn(length = 3, discriminatorType = DiscriminatorType.STRING, columnDefinition = "CHAR(3) NOT NULL", name = "type")
  public class People implements Serializable {
  </code></pre>
  
  <p>I couldn't find a way to change it into documentation.</p>