JpaRepository: Spring Sort for runtime query variabels - sql

Question

There is my plain sql query:
SELECT id, title,
IF(o.fixed_on_top = 1 AND o.fixing_on_top_day_counter > 5, 1 ,0) actual_fixed_on_top
FROM orders o
ORDER BY actual_fixed_on_top DESC, publication_date DESC;
How can I perform sorting like this on JpaRepository?
Maybe using Criteria API?
But I dint find any examples..
Thanks!
EDIT:
ok, studied different ways, and convinced that it cant be implemented through Criteria API (but it is a pity)
One working variant: Native SQL Query, i am sure.

Answer 1

You can do it by using the QueryDslPredicateExecutor which provides the following two method:
Iterable<T> findAll(Predicate predicate, OrderSpecifier<?> ... orderSpecifiers);
Page<T> findAll(Predicate predicate, Pageable pageable);
The PageRequest class implements Pageable and allows you to specified the sorting you want.
You could also add a Pageable parameter in a #Query annotated method on a regular JpaRepository and Spring Data Jpa will do the rest, for example:
#Query("select e from SomeEntity e where e.param1 = :param1")
public Page<SomeEntity> findSome(#Param("param1") String param1, Pageable pageable);

Answer 2

(sorry cannot comment yet)
I recently had the same issue.
The only solution worked for me, is to specify the order on the relationship.
I don't see a relationship in your query
example:
#OneToMany
#OrderBy("date")
...

Answer 3

Spring data jpa does understand order by see doc
findByAgeOrderByLastnameDesc() will be parsed into where x.age = ?1 order by x.lastname desc clause.
I see your case a bit complicated, but you can do JQPL with #Query annotation, Sample:
#Query("SELECT o FROM Order o WHERE write your clause ORDER BY o.something desc")
public Order findByCustomPK(#Param("paramIfNeeded"));

Answer 4

I found the solution:
public class MyEntitySpecifications {
public static Specification<MyEntity> GetByPageSpecification() {
return new Specification<MyEntity>() {
#Override
public Predicate toPredicate(Root<MyEntity> root, CriteriaQuery<?> cq, CriteriaBuilder cb) {
Expression fixingExpr = cb.greaterThan(root.get(MyEntity_.fixingDueDate), new DateTime(DateTimeZone.UTC));
cq.orderBy(new OrderImpl(cb.selectCase().when(fixingExpr, 1).otherwise(0), false));
return cb...;
}
};
}
}
The main idea is using case expression instead of simple logical.
plain sql equuivalent is:
select ...
from my_entity e
where ...
order by case when e.fixing_due_date > now() then 1 else 0 end desc
So we can build dynamic queries with criteria api specifications as well.
No direct access to EntityManager, no plain sql.