Jpa中的一對多關系

Question

我想從具有 1-M 關系的實體獲取數據。 用戶有一個 cv 信息的實體。使用 JpaRepo，Cv class：

@Entity
@Table(name = "cvs")
@Data
@AllArgsConstructor
@NoArgsConstructor
@JsonIgnoreProperties({"hibernateLazyInitializer", "handler", "educations", "works", "langueges", "technologies"})
public class CV {

    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    @Column(name = "id")
    private int id;

    //ToDo : Employee bilgilerinin görünmesi problemi giderilecek.
    @OneToOne
    @JoinColumn(name = "employee_id")
    private Employee employee;

    @OneToMany(mappedBy = "cv", cascade = CascadeType.ALL, orphanRemoval = true)
    List<Education> educations;

    @OneToMany(mappedBy = "cv", cascade = CascadeType.ALL, orphanRemoval = true)
    List<Work> works;

    @OneToMany(mappedBy = "cv", cascade = CascadeType.ALL, orphanRemoval = true)
    List<Languege> langueges;

    @OneToMany(mappedBy = "cv", cascade = CascadeType.ALL, orphanRemoval = true)
    List<Technology> technologies;

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

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

    @NotNull
    @NotBlank
    @Column(name = "cover_letter")
    private String coverLetter;

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

這是教育 class（工作、語言、技術課程相同）：

@Data
@AllArgsConstructor
@NoArgsConstructor
@Entity
@Table(name = "cv_educations")
public class Education {

    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    @Column(name = "id")
    private int id;

    @NotNull
    @NotBlank
    @Column(name = "school_name")
    private String schoolName;

    @NotNull
    @NotBlank
    @Column(name = "department")
    private String department;

    @NotNull
    @NotBlank
    @PastOrPresent
    @Column(name = "starting_date")
    @DateTimeFormat(pattern = "yyyy-mm-dd")
    private LocalDate startingDate;

    @NotBlank
    @Column(name = "graduation_date")
    @DateTimeFormat(pattern = "yyyy-mm-dd")
    private LocalDate graduationDate;

    @ManyToOne
    @JoinColumn(name = "cv_id")
    private CV cv;
}

我嘗試用 jpa 構建以下結構，但構造函數采用列表參數。 我得到一個錯誤，因為我不能用 jpql 寫它

public interface CvRepository extends JpaRepository<CV, Integer> {

        @Query("select new com.demo.humanresourcesmanagementsystem.Entities.concretes.CV" +
                "(employee.firstName, employee.lastName, cv.github, cv.linkedin, cv.coverLetter," +
                "educations, works, langueges, technologies)" +
                "from CV cv inner join cv.employee employee inner join cv.educations educations " +
                "inner join cv.works works inner join cv.langueges langueges " +
                "inner join cv.technologies technologies where cv.employee.id =:employeeId")
        CV findByCv(int employeeId);
    }

我想閱讀有關該實體的教育、作品、語言和技術的信息。 也就是說會有一個cv為output，但是cv里面可能有不止一個學歷object（比如小學，高中），傳入的數據會是下面的格式，例如：

"firstName": "X",
"lastName" : "X",
"educations" : [
           "education1" {
                  "school" : "x", 
                  "department" : "x" ...}, 
           "education2" {
                  "school" : "x", 
                  "department" : "x"...}
"works" : [
    "work1" {
           "workplace" : "x", 
           "job" : "x" ...
          }
       ]
"github" : "x",
"linkedin" : "x"

我如何使用 jpa 存儲庫設置此結構？ 如果我要使用它，我應該寫什么樣的 dto？ 謝謝。

更新

當我使用 spring jpa 派生查詢 (findByEmployeeId) 時，我收到的數據格式如下：

{
  "success": true,
  "message": "string",
  "data": {
    "id": 0,
    "employee": {
      "id": 0,
      "email": "string",
      "password": "string",
      "firstName": "string",
      "lastName": "string",
      "nationalIdentity": "string",
      "yearOfBirth": 0
    },
    "github": "string",
    "linkedin": "string",
    "coverLetter": "string",
    "photo": "string"
  }
}

所以我無法接收有關教育、工作、語言和技術的數據。

Answer 1

您似乎正在嘗試通過其employer.id檢索簡歷。 在這種情況下，您實際上可以只使用包含關鍵字的 JPA 查詢方法。 在這種情況下，它看起來像：

CV findByEmployeeId(int employeeId);

這應該會如您所料返回完整的CV object。

有關 JPA 查詢方法關鍵字的更多詳細信息，請參見此處。