Package org.hibernate.query.criteria

Class CriteriaDefinition<R>

java.lang.Object
org.hibernate.query.criteria.spi.HibernateCriteriaBuilderDelegate
org.hibernate.query.criteria.CriteriaDefinition<R>
Type Parameters:
R - the query result type
All Implemented Interfaces:
AbstractQuery<R>, CommonAbstractCriteria, CriteriaBuilder, CriteriaQuery<R>, CriteriaSelect<R>, Serializable, HibernateCriteriaBuilder, JpaCriteriaBase, JpaCriteriaNode, JpaCriteriaQuery<R>, JpaCriteriaSelect<R>, JpaCteContainer, JpaQueryableCriteria<R>, JpaSelectCriteria<R>
@Incubating public abstract class CriteriaDefinition<R> extends HibernateCriteriaBuilderDelegate implements JpaCriteriaQuery<R>
A utility class that makes it easier to build criteria queries. From within an initializer block of a (usually anonymous) subclass, all operations of the CriteriaBuilder and CriteriaQuery may be called without the need for specifying the target object.

For example: 

 sessionFactory.inTransaction(session -> {
     List<Book> books
             = new CriteriaDefinition<>(sessionFactory, Book.class) {{
                 var book = from(Book.class);
                 where(like(book.get(Book_.title), "%Hibernate%"));
                 orderBy(desc(book.get(Book_.publicationDate)), asc(book.get(Book_.isbn)));
                 book.fetch(Book_.authors);
             }}
             .createSelectionQuery(session)
             .setMaxResults(10)
             .getResultList();
     ...
 });

A CriteriaDefinition may even be used to modify a base HQL or criteria query: 

 sessionFactory.inTransaction(session -> {
     List<Book> books
             = new CriteriaDefinition<>(sessionFactory, Book.class,
                     "from Book left join fetch authors where type = BOOK") {{
                 var book = getRoot(0, Book.class);
                 where(getRestriction(), like(book.get(Book_.title), "%Hibernate%"));
                 orderBy(desc(book.get(Book_.publicationDate)), asc(book.get(Book_.isbn)));
             }}
             .createSelectionQuery(session)
             .getResultList();
     ...
 });
For queries which don't change between executions, the CriteriaDefinition may be safely built and cached at startup: 
 // build and cache the query
 static final CriteriaQuery<Book> bookQuery =
         new CriteriaDefinition<>(sessionFactory, Book.class) {{
             var book = from(Book.class);
             where(like(book.get(Book_.title), "%Hibernate%"));
             orderBy(desc(book.get(Book_.publicationDate)), asc(book.get(Book_.isbn)));
             book.fetch(Book_.authors);
         }};

 ...

 // execute it in a session
 sessionFactory.inTransaction(session -> {
     List<Book> books =
             session.createQuery(bookQuery)
                     .setMaxResults(10)
                     .getResultList();
     ...
 });
A CriteriaDefinition may be used to modify another CriteriaDefinition: 
 var bookFilter
         = new CriteriaDefinition<>(sessionFactory, Book.class) {{
             where(like(from(Book.class).get(Book_.title), "%Hibernate%"));
         }};
 long count
         = new CriteriaDefinition<>(bookFilter, Long.class) {{
             select(count());
         }}
         .createSelectionQuery(session)
         .getSingleResult();
 var books =
         = new CriteriaDefinition<>(bookFilter) {{
             var book = (Root<Book>) getRootList().get(0);
             book.fetch(Book_.authors);
             orderBy(desc(book.get(Book_.publicationDate)), asc(book.get(Book_.isbn)));
         }}
         .createSelectionQuery(session)
         .setMaxResults(10)
         .getResultList();
Since:
6.3
See Also: