SqlResultSetMapping or NamedNativeQuery annotation to map the SELECT clause of a SQL query to a constructor.">
Jakarta Persistence (JPA) Annotation Type

jakarta.persistence.ConstructorResult

Implemented Interfaces:
Annotation
Used in conjunction with the SqlResultSetMapping or NamedNativeQuery 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)
             })
     })
See Also:
Since:
Jakarta Persistence (JPA) 2.1

Annotation Elements

Class<?> targetClass
(Required) The class whose constructor is to be invoked.
Since:
Jakarta Persistence (JPA) 1.0
ColumnResult[] columns
(Required) The mapping of columns in the SELECT list to the arguments of the intended constructor, in order.
Since:
Jakarta Persistence (JPA) 1.0

Additional JDK methods inherited from java.lang.annotation.Annotation

annotationType(), equals(Object), hashCode(), toString()