java - Spring-JPA - 如何从自连接表输出有限字段

Question

我有一个名为员工的实体，它具有 self 连接。该连接代表谁是该员工的经理。当我查询记录时，我得到了员工的整个层次结构。

我希望实现的是仅获取经理的几个字段，并且不希望获取员工的经理的经理。

我尝试使用@NamedEntityGraph执行此操作，但无法获得预期的输出。也使用了投影。

我也尝试了这里提到的方法

1. JPA Self Join using JoinTable

2. Self join Spring JPA

注意 - 我不想使用@Query注释

@Entity
public class Employee {
    @Id
    @Column(name = "employeeId", nullable = false)
    private String employeeId;

    @Column(name = "firstName", nullable = false)
    private String firstName;

    @Column(name = "lastName", nullable = false)
    private String lastName;

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

    @Column(name = "dateOfJoining", nullable = false)
    private LocalDate dateOfJoining;

    @ManyToOne(cascade = CascadeType.ALL)
    @JoinColumn(name = "line_manager_id")
    private Employee manager;

}

实际结果 -

{
   "firstName":"Super",
   "lastName":"Manager",
   "middleName":"",
   "dateOfJoining":"2012-12-31",
   "manager":{
      "firstName":"Super",
      "lastName":"Manager",
      "middleName":"",
      "dateOfJoining":"2012-12-31",
      "manager":{
         "firstName":"Admin",
         "lastName":"User",
         "middleName":"",
         "dateOfJoining":"2012-12-31",
         "manager":{
            "firstName":"Admin",
            "lastName":"User",
            "middleName":"",
            "dateOfJoining":"2012-12-31",
            "manager": null,
            "employeeId":"P67"
         },
         "employeeId":"P68"
      },
      "employeeId":"P69"
   },
   "employeeId":"P70"
}

预期结果

{
   "firstName":"Super",
   "lastName":"Manager",
   "middleName":"",
   "dateOfJoining":"2012-12-31",
   "manager":{
      "firstName":"Super",
      "lastName":"Manager",
      "employeeId":"P69"
   },
   "employeeId":"P70"
}

Answer 1

您应该在不想包含的字段中使用@JsonIgnore注释。检查here和 here了解更多信息。