12.4.16. About HQL Ordering
The results of the query can also be ordered. The
ORDER BY
clause is used to specify the selected values to be used to order the result. The types of expressions considered valid as part of the order-by clause include:
- state fields
- component/embeddable attributes
- scalar expressions such as arithmetic operations, functions, etc.
- identification variable declared in the select clause for any of the previous expression types
HQL does not mandate that all values referenced in the order-by clause must be named in the select clause, but it is required by JPQL. Applications desiring database portability should be aware that not all databases support referencing values in the order-by clause that are not referenced in the select clause.
Individual expressions in the order-by can be qualified with either
ASC
(ascending) or DESC
(descending) to indicated the desired ordering direction.
Example 12.20. Order-by Examples
// legal because p.name is implicitly part of p select p from Person p order by p.name select c.id, sum( o.total ) as t from Order o inner join o.customer c group by c.id order by t