假设实体客户具有如下OneToMany属性：
@OneToMany(mappedBy = "customerId")
private Collection<Order> orders;
您可以使用以下查询：
EntityManager em; // to be built or injected
CriteriaBuilder cb = em.getCriteriaBuilder();
CriteriaQuery<Tuple> cq = cb.createTupleQuery();
Root<Customer> customer = cq.from(Customer.class);
CollectionJoin<Customer, Order> orders = customer.join(Customer_.orders, JoinType.LEFT);
cq.select(cb.tuple(customer, cb.count(orders)));
cq.where(... add some predicates here ...);
cq.groupBy(customer.get(Customer_.id));
cq.orderBy(cb.desc(cb.count(orders)));
List<Tuple> result = em.createQuery(cq).getResultList();
for (Tuple t : result) {
Customer c = (Customer) t.get(0);
Long cnt = (Long) t.get(1);
System.out.println("Customer " + c.getName() + " has " + cnt + " orders");
}
上面的方法使用Metamodel。如果你不喜欢它，你可以替换Customer_.orders使用"orders"，并Customer_.id用"id"。
如果OneToMany财产是另一种类型的，更换CollectionJoin用正确类型的集合（ListJoin，SetJoin，MapJoin）。
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