获取@ManyToOne字段数据时出现问题

Question

I am not getting data of @ManyToOne field.

@Entity
public class UserDetail {

    @OneToMany(cascade = { CascadeType.ALL })
    @JoinColumn(name = "user_id")
    @JsonIgnore
    private List<UserOrder> orders;
}

@Entity
public class UserOrder {

    @ManyToOne
    @JoinColumn(name = "user_id")
    @JsonBackReference
    private UserDetail userDetail;

    @ManyToOne
    @JoinColumn(name = "runner_id")
    @JsonBackReference(value="runner")
    private UserDetail runner;

}

List<UserOrder> findAllByStatusNotInOrderByOrderDateDesc(List<OrderStatus> orderStatuses);

when i am fetching list of orders, i am expecting userdetail and runner in result, but i am not getting anything in JSON output.

Answer 1

You need to include the lazy load relation into the result.

@EntityGraph(attributePaths = "runner")
List<UserOrder> findAllByStatusNotInOrderByOrderDateDesc(List<OrderStatus> orderStatuses);

Or just set it eager load

Answer 2

Try to set the relation between those two entities in this way:

@Entity
public class UserDetail {

    @OneToMany(mappedBy="userDetail", cascade = { CascadeType.ALL })
    @JsonIgnore
    private List<UserOrder> orders;

    @OneToMany(mappedBy="runner", cascade = { CascadeType.ALL })
    @JsonIgnore
    private List<UserOrder> runnerOrders;
}



@Entity
public class UserOrder {

    @ManyToOne
    @JoinColumn(name = "user_id")
    @JsonBackReference
    private UserDetail userDetail;

    @ManyToOne
    @JoinColumn(name = "runner_id")
    @JsonBackReference(value="runner")
    private UserDetail runner;

}