Annotation Interface ConstructorResult


@Target({}) @Retention(RUNTIME) public @interface ConstructorResult
Used in conjunction with the SqlResultSetMapping annotation to map the SELECT clause of a SQL query to a constructor.

Applies a constructor for the target class, passing in as arguments values from the specified columns. All columns corresponding to arguments of the intended constructor must be specified using the columns element of the ConstructorResult annotation in the same order as that of the argument list of the constructor. Any entities returned as constructor results will be in either the new or detached state, depending on whether a primary key is retrieved for the constructed object.


 Example:

   Query q = em.createNativeQuery(
      "SELECT c.id, c.name, COUNT(o) as orderCount, AVG(o.price) AS avgOrder " +
      "FROM Customer c, Orders o " +
      "WHERE o.cid = c.id " +
      "GROUP BY c.id, c.name",
      "CustomerDetailsResult");

   @SqlResultSetMapping(
       name="CustomerDetailsResult",
       classes={
          @ConstructorResult(
               targetClass=com.acme.CustomerDetails.class,
                 columns={
                    @ColumnResult(name="id"),
                    @ColumnResult(name="name"),
                    @ColumnResult(name="orderCount"),
                    @ColumnResult(name="avgOrder", type=Double.class)
                    }
          )
       }
      )

 
Since:
2.1
See Also:
  • Required Element Summary

    Required Elements
    Modifier and Type
    Required Element
    Description
    (Required) The mapping of columns in the SELECT list to the arguments of the intended constructor, in order.
    (Required) The class whose constructor is to be invoked.
  • Element Details

    • targetClass

      Class targetClass
      (Required) The class whose constructor is to be invoked.
    • columns

      ColumnResult[] columns
      (Required) The mapping of columns in the SELECT list to the arguments of the intended constructor, in order.