如何在 JpaRepository 中将多个查询写入一个映射实体

Question

我有两个实体，并使用多对一注释来映射它们，但是在使用另一个表id编写了查找对象的查询后，当我注释掉调用该应用程序的行和方法时，出现了一个错误，但是我想实现该功能，请帮助我

这些是我的实体类：

@Entity
@Table(name = "Contract")
public class  Contract implements Serializable {
    @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    @Column(name = "contractId")
    private long contractId;

    @Column(name="start_date")
    private Date st_date;

    @Column(name="end_date")
    private Date end_date;

    @ManyToOne(fetch = FetchType.LAZY, optional = false)
    @JoinColumn(name = "hotel_id", nullable = false)
    @OnDelete(action = OnDeleteAction.CASCADE)
    @JsonIgnore
    private Hotel hotel;

    // getters and setters

第二个实体

@Entity
@Table(name="Hotel")
public class Hotel {
    @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    @Column(name="hotel_id")
    private long hotel_id;
    @Column(name="hotel_name")
    private String hotel_name;
    @Column(name="hotel_location")
    private String hotel_location;
    @Column(name="hotel_email")
    private String hotel_email;
    @Column(name="hotel_telephone")
    private String hotel_telephone
   // getters and setters

我的合同服务类

@Service
public class ContractService {
    @Autowired
    private ContractRepository contractRepository;

    @Autowired
    private HotelRepository hotelRepository;

    public List<Contract> getAllContracts(){
        return contractRepository.findAll();
    }

    public List<Contract> findByHotelId(Long hotelId,Pageable pageable){
        return contractRepository.findByHotelId(hotelId, pageable);
    }
    public ResponseEntity<?> deleteContract(Long hotelId, Long contractId)                
    {
    return contractRepository.findByIdAndHotelId(contractId,         
    hotelId).map(Contract -> {
        contractRepository.delete(Contract);
        return ResponseEntity.ok().build();
    }).orElseThrow(() -> new ResourceNotFoundException("Comment not found 
    with ContractId " + contractId + " and hotelId " + hotelId));
}

我的合同存储库

@Repository
public interface ContractRepository extends JpaRepository<Contract, Long> {
    List<Contract> findByHotelId(Long hotelId, Pageable pageable);
    Optional<Contract> findByIdAndHotelId(Long id, Long hotelId);
}

我在运行项目时遇到此错误

org.springframework.beans.factory.未满足的依赖异常：创建名称为“合同控制器”的bean时出错：通过字段“合同服务”表示的依赖项未满足；嵌套异常是org.springframework.beans.factory.未满足的依赖异常：创建名称为“合同服务”的bean时出错：通过字段“合同存储库”表示的依赖项未满足；嵌套异常是org.springframework.beans.factory.BeanCreation异常：创建名称为“合同存储库”的bean时出错：初始化方法调用失败；嵌套异常是java.lang.IllegalArgument异常：未能创建方法公共抽象java.util.列表com.sunTravel.sunRest.repository.ContractRepository.findByHotelId（java.lang.长，org.springframework.data.domain.可分页）的查询！未找到酒店类型的属性ID！遍历路径：Contract.hotel.

Answer 1

您应该将主键从hotel_id重命名为id，然后只有存储库方法才能工作。

@Entity
@Table(name="Hotel")
public class Hotel {
    @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    @Column(name="hotel_id")
    private long id;
    @Column(name="hotel_name")
    private String hotel_name;
    @Column(name="hotel_location")
    private String hotel_location;
    @Column(name="hotel_email")
    private String hotel_email;
    @Column(name="hotel_telephone")
    private String hotel_telephone
   // getters and setters

Answer 2

第一个解决方案：基于堆栈跟踪，Spring数据在Hotel类中查找id变量（主键）。所以请更改＜code＞private long hotel_id到私有长id

另一个解决方案(无需做任何更改，只需添加您自己的查询):

使用< code>@Query编写自己的JPA查询。

示例:

@Query("SELECT contract from Contract as contract where contract.hotel.hotel_id = :hotelId")
List<Contract> findByHotelId(Long hotelId, Pageable pageable);