Hibernate - HQL and JPQL Query API (Hibernate Query API)

In Hibernate, the HQL query is represented as org.hibernate.query.Query which is obtained from a Session. If the HQL is a named query, Session#getNamedQuery would be used; otherwise Session#createQuery is needed.

Obtaining a Hibernate Query

org.hibernate.query.Query query = session.createQuery(
"select p " +
"from Person p " +
"where p.name like :name"
);

Obtaining a Hibernate Query reference for a named query

org.hibernate.query.Query query = session.getNamedQuery( "get_person_by_name" );

Basic Query usage - Hibernate

org.hibernate.query.Query query = session.createQuery(
"select p " +
"from Person p " +
"where p.name like :name" )
// timeout - in seconds
.setTimeout( 2 )
// write to L2 caches, but do not read from them
.setCacheMode( CacheMode.REFRESH )
// assuming query cache was enabled for the SessionFactory
.setCacheable( true )
// add a comment to the generated SQL if enabled via the hibernate.use_sql_comments configuration property
.setComment( "+ INDEX(p idx_person_name)" );

Hibernate name parameter binding

org.hibernate.query.Query query = session.createQuery(
"select p " +
"from Person p " +
"where p.name like :name" )
.setParameter( "name", "J%", StringType.INSTANCE );
Hibernate generally understands the expected type of the parameter given its context in the query. In the previous example since we are using the parameter in a LIKE comparison against a String-typed attribute Hibernate would automatically infer the type; so the above could be simplified.

Hibernate name parameter binding (inferred type)

org.hibernate.query.Query query = session.createQuery(
"select p " +
"from Person p " +
"where p.name like :name" )
.setParameter( "name", "J%" );

Hibernate name parameter binding (short forms)

org.hibernate.query.Query query = session.createQuery(
"select p " +
"from Person p " +
"where p.name like :name " +
"  and p.createdOn > :timestamp" )
.setParameter( "name", "J%" )
.setParameter( "timestamp", timestamp, TemporalType.TIMESTAMP);

Hibernate list() result

List<Person> persons = session.createQuery(
"select p " +
"from Person p " +
"where p.name like :name" )
.setParameter( "name", "J%" )
.list();

Hibernate uniqueResult()

Person person = (Person) session.createQuery(
"select p " +
"from Person p " +
"where p.name like :name" )
.setParameter( "name", "J%" )
.uniqueResult();

Scrolling through a ResultSet containing entities

try ( ScrollableResults scrollableResults = session.createQuery(
"select p " +
"from Person p " +
"where p.name like :name" )
.setParameter( "name", "J%" )
.scroll()
) {
while(scrollableResults.next()) {
Person person = (Person) scrollableResults.get();
process(person);
}
}

Hibernate stream() using a projection result type

try ( Stream<Object[]> persons = session.createQuery(
"select p.name, p.nickName " +
"from Person p " +
"where p.name like :name" )
.setParameter( "name", "J%" )
.stream() ) {

persons
.map( row -> new PersonNames(
(String) row[0],
(String) row[1] ) )
.forEach( this::process );
}

Hibernate stream() using an entity result type

try( Stream<Person> persons = session.createQuery(
"select p " +
"from Person p " +
"where p.name like :name" )
.setParameter( "name", "J%" )
.stream() ) {

Map<Phone, List<Call>> callRegistry = persons
.flatMap( person -> person.getPhones().stream() )
.flatMap( phone -> phone.getCalls().stream() )
.collect( Collectors.groupingBy( Call::getPhone ) );

process(callRegistry);
}