Question

我已经定义了用户和位置之间的多对多关系，并且运行良好；当我必须使用组合键的一部分来执行数据检索时，所有问题都已经开始。

业务用户模型定义如下：

    @Table(name = "BusinessUser")
public class User {
    private String userId;
    private String userAuthId;
    private Set<UserLocation> userLocations;

    @Id
    public String getUserId () {
        return userId;
    }

    public void setUserId ( String userId ) {
        this.userId = userId;
    }

    public User () {
        userLocations = new HashSet<>();
    }
    @JsonManagedReference
    @OneToMany(mappedBy = "user", cascade = CascadeType.ALL, orphanRemoval = true)
    public Set<UserLocation> getUserLocations () {
        return userLocations;
    }

    public void setUserLocations ( Set<UserLocation> userLocations ) {
        this.userLocations = userLocations;
    }
}

位置实体的定义如下：

    public class Location {
    private String locationId;
    private String googlePlacesId;
    private Set<UserLocation> userLocations;

    @Id
    public String getLocationId () {
        return locationId;
    }

    public void setLocationId ( String locationId ) {
        this.locationId = locationId;
    }

    public Location () {
        userLocations = new HashSet<>();
    }
    @JsonManagedReference
    @OneToMany(mappedBy = "location")
    public Set<UserLocation> getUserLocations () {
        return userLocations;
    }

    public void setUserLocations ( Set<UserLocation> userLocations ) {
        this.userLocations = userLocations;
    }
}

和UserLocation表如下：

@Entity
@Table(name="user_location")
@IdClass(UserLocation.UserLocationId.class)
public class UserLocation implements Serializable {

    private User user;
    private Location location;
    private Date createdDate;

    @Id
    @ManyToOne
    @JsonBackReference
    @JoinColumn(name = "userId")
    public User getUser () {
        return user;
    }

    public void setUser ( User user ) {
        this.user = user;
    }

    @Id
    @ManyToOne
    @JsonBackReference
    @JoinColumn(name = "locationId")
    public Location getLocation () {
        return location;
    }

    public void setLocation ( Location location ) {
        this.location = location;
    }

    public Date getCreatedDate () {
        return createdDate;
    }

    public void setCreatedDate ( Date createdDate ) {
        this.createdDate = createdDate;
    }

这样做是为了确保用户和位置之间的映射一致。但是现在出现了问题。我有一个用户ID，在此基础上，我需要从UserLocation表中检索所有LocationId。获得所有位置ID后，便可以检索所有位置对象。

我的UserLocation JPAR存储库已创建如下：

@Repository
public interface UserLocationRepository extends JpaRepository<UserLocation,Long> {
    List<UserLocation> findByUser ( User user);
}

这是定义这种关系的最佳方法。如何只给定userID来检索Location的值我可以看到一个IdClass错误，该错误已为其定义了ID类并添加了相同的类。一旦这样做，我会看到一个持久ID错误。有线索吗？

SpringBoot复合键查询；如何从组合键的一部分中检索值

0 个答案: