Jpa 尝试按crudrepository中关联实体的字段排序时出现spring数据错误

我在Mysql中使用springboot和springdata

我有两个实体，客户和订单：

@Entity
@Table(name = "customers")
public class Customer {

    @Id
    @GeneratedValue(strategy= GenerationType.IDENTITY)
    @Column(name="id", nullable = false)
    protected long id;

    @Column(name = "name")
    private String name;
}

@Entity
@Table(name = "orders")
public class Order {

    @Id
    @GeneratedValue(strategy= GenerationType.IDENTITY)
    @Column(name="id", nullable = false)
    protected long id;

    @Column(name="customer_id")
    private long customerId;
}

我还有一个存储库：

@Repository
public interface OrdersRepository extends JpaRepository<Order, Long> {

    @Query("select o from Order o, Customer c where o.customerId = c.id")
    Page<Order> searchOrders(final Pageable pageable);
}

但是，按顺序字段排序效果良好：

Sort sort = new Sort(Sort.Direction.ASC, "id");
ordersRepository.search(new PageRequest(x, y, sort));

我得到的错误是c不是Order属性（但由于查询是实体的连接，我希望它能够工作）

您知道我如何按照联接实体的字段进行排序吗

---

谢谢您

在JPA中，您使用的排序对象必须是select语句中返回的对象，您不能使用未返回的属性进行排序

您收到了错误，因为关系建模不正确。在您的情况下，这是一种

manytone

关系。我可以推荐这本书进一步阅读

@Entity
@Table(name = "orders")
public class Order {

    @Id
    @GeneratedValue(strategy= GenerationType.IDENTITY)
    @Column(name="id", nullable = false)
    protected long id;

    @ManyToOne
    @JoinColumn(name="customer_id", referencedColumnName = "id")
    private Customer customer;
}

不再需要查询，因为将获取客户

@Repository
public interface OrdersRepository extends PagingAndSortingRepository<Order, Long> {
}

@Entity
@Table(name = "orders")
public class Order {

    @Id
    @GeneratedValue(strategy= GenerationType.IDENTITY)
    @Column(name="id", nullable = false)
    protected long id;

    @ManyToOne
    @JoinColumn(name="customer_id", referencedColumnName = "id")
    private Customer customer;
}

@Repository
public interface OrdersRepository extends PagingAndSortingRepository<Order, Long> {
}

Sort sort = new Sort(Sort.Direction.ASC, "customer.name");
ordersRepository.findAll(new PageRequest(x, y, sort));