javax.persistence
Annotation Type ConstructorResult

@Target(value={})
@Retention(value=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"
    );









Required Element Summary




 ColumnResult[]
columns



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



 java.lang.Class
targetClass



          (Required) The class whose constructor is to be invoked.


 





Element Detail



targetClass
public abstract java.lang.Class targetClass

(Required) The class whose constructor is to be invoked.










columns
public abstract ColumnResult[] columns

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