@Entity
@Table(name = "MY_TABLE")
public class MyEntity {

	@Id
	@GeneratedValue(strategy = GenerationType.AUTO)
	@Column(name = "ID")
	private Integer id;

	@Column(name = "amount")
	private Integer amount;

	@JoinColumn(name = "REL_ENTITY", foreignKey = @ForeignKey(name = "FK_REL_ENT_01"))
	@ManyToOne
	@Fetch(FetchMode.SELECT)
	private RelatedEntity relatedEntity;
}

@Entity
@Table(name = "MY_TABLE")
@DiscriminatorColumn(name = "DISC_COL", discriminatorType = DiscriminatorType.INTEGER)
@Cache(usage = CacheConcurrencyStrategy.READ_WRITE)
public abstract class RelatedEntity {

	@Id
	@GeneratedValue(strategy = GenerationType.AUTO)
	@Column(name = "ID")
	Integer id;

	@Column(name = "RELATED_VALUE")
	Integer value;
}

@Entity
@DiscriminatorValue("1")
public class ChildOneEntity extends RelatedEntity {
	@Column(name = "ONLY_CHILD_ONE")
	private Integer onlyChildOne;
}

@Entity
@DiscriminatorValue("2")
public class ChildTwoEntity extends RelatedEntity {
	@Column(name = "ONLY_CHILD_TWO")
	private Integer onlyChildTwo;
}

public class MyPojo {
	Integer amount;
	RelatedEntity relatedEntity;

	public MyPojo(Integer amount, RelatedEntity relatedEntity) {
		this.amount = amount;
		this.relatedEntity = relatedEntity;
	}
}

	@Test
	public void failingTest() throws Exception {
		// BaseCoreFunctionalTestCase automatically creates the SessionFactory and
		// provides the Session.
		try (Session s = openSession()) {
			Transaction tx = s.beginTransaction();
			String hql = "select new org.hibernate.bugs.MyPojo (sum(e.amount), re ) from org.hibernate.bugs.MyEntity e join e.relatedEntity re where 1=1 group by re";
			Query<MyPojo> query = s.createQuery(hql, MyPojo.class);
			List<MyPojo> actual = query.list();
			assertThat(actual).isEmpty();

			// Verify the generated SQL
			// In oracle we get ORA-00979 not a group by expression
			tx.commit();
		}
	}

Hibernate:
    select
        sum(m1_0.amount),
        r1_0.ID,
        r1_0.DISC_COL,
        r1_0.RELATED_VALUE,
        r1_0.ONLY_CHILD_ONE,
        r1_0.ONLY_CHILD_TWO
    from
        MY_TABLE m1_0
    join
        MY_TABLE r1_0
            on r1_0.ID=m1_0.REL_ENTITY
    where
        1=1
    group by
        r1_0.ID,
        r1_0.DISC_COL,
        r1_0.RELATED_VALUE