2.3. Mapping Queries
2.3.Mapping JPAQL/HQL queries. Mapping JPAQL/HQL queries
You can map EJBQL/HQL queries using annotations.
@NamedQuery and @NamedQueries can be defined at the class level or in a JPA XML file. However their definitions are global to the session factory/entity manager factory scope. A named query is defined by its name and the actual query string.
<entity-mappings>
<named-query name="plane.getAll">
<query>select p from Plane p</query>
</named-query>
...
</entity-mappings>
...
@Entity
@NamedQuery(name="night.moreRecentThan", query="select n from Night n where n.date >= :date")
public class Night {
...
}
public class MyDao {
doStuff() {
Query q = s.getNamedQuery("night.moreRecentThan");
q.setDate( "date", aMonthAgo );
List results = q.list();
...
}
...
}
You can also provide some hints to a query through an array of
QueryHint through a hints attribute.
The availabe Hibernate hints are
| hint | description |
|---|---|
| org.hibernate.cacheable | Whether the query should interact with the second level cache (default to false) |
| org.hibernate.cacheRegion | Cache region name (default used otherwise) |
| org.hibernate.timeout | Query timeout |
| org.hibernate.fetchSize | resultset fetch size |
| org.hibernate.flushMode | Flush mode used for this query |
| org.hibernate.cacheMode | Cache mode used for this query |
| org.hibernate.readOnly | Entities loaded by this query should be in read only mode or not (default to false) |
| org.hibernate.comment | Query comment added to the generated SQL |
