Package org.hibernate.annotations

Annotation Interface DiscriminatorFormula

@Target(TYPE) @Retention(RUNTIME) public @interface DiscriminatorFormula
Specifies an expression written in native SQL as the discriminator for an entity inheritance hierarchy. Must be used to annotate the root entity of the hierarchy.

Used in place of the JPA DiscriminatorColumn.

For example, we might declare a supertype as follows: 

 @Entity
 @DiscriminatorFormula(discriminatorType = INTEGER,
                value = "case when value1 is not null then 1 when value2 is not null then 2 end")
 public abstract class AbstractChild {
     @Id
     @GeneratedValue
     Integer id;
     ...
 }

and then each concrete subclass must specify a matching discriminator value: 

 @Entity
 @DiscriminatorValue("1")
 public class ConcreteChild1 extends AbstractChild {
     @Basic(optional = false)
     @Column(name = "VALUE1")
     String value;
     ...
 }
 
 @Entity
 @DiscriminatorValue("2")
 public class ConcreteChild2 extends AbstractChild {
     @Basic(optional = false)
     @Column(name = "VALUE2")
     String value;
     ...
 }
See Also:

  • Required Element Summary

    Required Elements
    Modifier and Type
    Required Element
    Description
    String
    value
    The formula string.

  • Optional Element Summary

    Optional Elements
    Modifier and Type
    Optional Element
    Description
    DiscriminatorType
    discriminatorType
    The type of value returned by the formula.

  • Element Details

    • value

      String value
      The formula string.

    • discriminatorType

      DiscriminatorType discriminatorType
      The type of value returned by the formula.

      This is required, unless the expression is of type varchar or similar.

      Default:
      STRING