@Target(value={})
@Retention(value=RUNTIME)
public @interface ConstructorResult
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)
}
)
}
)
SqlResultSetMapping,
ColumnResult| Modifier and Type | Required Element and Description |
|---|---|
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.
|
public abstract java.lang.Class targetClass
public abstract ColumnResult[] columns