Question

I have a table in database and a function that takes the table’s id and returns some number, for instance (I use Oracle syntax, but I believe RDMS doesn’t really matter in this case),

CREATE TABLE test1( test1_id INT NOT NULL PRIMARY KEY,
val VARCHAR(50));
CREATE FUNCTION getNum (id IN test1.test1_id%type) RETURN NUMBER IS ....

In my hibernate data object class I want to add a property which holds result of function execution. What is the right way to do so using annotations ?

@javax.persistence.Table(name = "test1", schema = "test", catalog = "")
@Entity
public class Test1Entity
{
      private int test1Id;
      @Column(name = "test1_id", nullable = false, insertable = true, 
      updatable = true, length = 22, precision = 0)
      @Id
      //get/set
      ...

      // is it possible to use annotations, 
      // so it will call a function to populate this field ?
      private BigDecimal test_num; 
}

I was thinking about creating naming native query , something like SELECT a.test1_id, a.val, getNum(a.test1_id) as test_num FROM test1 a WHERE a.test1_id = :param_test1_id, but it means I cannot use Session.get for reading object from DB.

Thank you.

Answer 1

Use this:

@Formula( "getNum(test1_id)" )
private BigDecimal test_num;