JPA select List<Object> from entity order by list elements attribute

Question

Im having a self reffering datamodel. Im trying to get a list of children ordered by an attribute using JPA (Hibernate). But Im having problems with the JPQL. Do you have a suggestion on how I can solve this?

Entity

@Entity
public class Foo {
    private String bar;
    private List<Foo> elements;
} 

JPQL

Demo JPQL to give you a hint of what Im trying to do

String jpql = "SELECT f.elements " +
              "FROM Foo f " +
              "Order By f.elements.bar";

Answer 1

您必须加入第二个表：

SELECT e FROM Foo f JOIN f.elements e ORDER BY e.bar