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)
})
})
SqlResultSetMapping, NamedNativeQuery, ColumnResult
| Modifier and Type | Method and Description |
|---|---|
| public ColumnResult[] | columns()
(Required) The mapping of columns in the SELECT list to the arguments of the intended constructor, in order. |
| public Class |
| columns | back to summary |
|---|---|
| public ColumnResult[] columns() (Required) The mapping of columns in the SELECT list to the arguments of the intended constructor, in order. | |
| targetClass | back to summary |
|---|---|
| public Class (Required) The class whose constructor is to be invoked. | |