Question

我有以下“父类”：

MainWindow::MainWindow(QWidget *parent) : QMainWindow(parent), ui(new Ui::MainWindow) {
  ui->setupUi(this);

  // Changes the dock widgets arrangement.
  splitDockWidget(ui->dock1, ui->dock3, Qt::Orientation::Horizontal);
  splitDockWidget(ui->dock1, ui->dock2, Qt::Orientation::Vertical);
}

我还有以下子类：

@Entity
@Table(name = "parent_table")
public class Parent {
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private Long parentId;

    private String firstName;
    private String lastName;

    @OneToMany(mappedBy = "Parent", cascade = CascadeType.ALL)
    List<Child> children;
 }

我在邮递员中发送以下请求：

@Entity
@Table(name = "children")
public class Child {

    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private Long childId;

    @ManyToOne
    @JoinColumn(name="parent_id")
    private Parent parent;

    private String name;
}

当我要求父级存储库保存父级时，它会保存，但是对于子级却什么也没有发生……它根本不会保存到数据库中……

作为参考，这是我保存父级的行

{
        "firstName": "Test",
        "lastName": "Parent",
        "children":[{
                "name":"jack"
            },
            {
                "name":"jill"
            }
        ]

}

（在这种情况下，父级内部有两个子级-但不会保存到子级表中）。

Answer 1

我运行了您的示例，它似乎运行正常，唯一改变的只是mappedBy批注的@OneToMany属性。它必须是小写的。

  @OneToMany(mappedBy = "parent", cascade = CascadeType.ALL, fetch = FetchType.EAGER)
  List<Child> children = new ArrayList<>();

父母

@Entity
@Table(name = "parent_table")
public class Parent {
  @Id
  @GeneratedValue(strategy = GenerationType.IDENTITY)
  @Column(name = "parent_id")
  private Long parentId;

  private String firstName;
  private String lastName;

  @OneToMany(mappedBy = "parent", cascade = CascadeType.ALL, fetch = FetchType.EAGER)
  List<Child> children = new ArrayList<>();
}

孩子

@Entity
@Table(name = "children")
public class Child {

  @Id
  @GeneratedValue(strategy = GenerationType.IDENTITY)
  private Long childId;

  @ManyToOne
  @JoinColumn(name="parent_id")
  private Parent parent;

  private String name;

}

测试

以上代码使下一个单元格成功：

  @Test
  public void parentRepositoryMustPersistParentAndChildren() {
    Parent parent = new Parent("Anakin", "Skywalker");
    parent.getChildren().add(new Child("Luke"));
    parent.getChildren().add(new Child("Leia"));

    Parent saved = parentRepository.save(parent);

    Assert.assertNull("Parent does not have and id assigned after persist it", saved.getParentId());
    saved.getChildren().forEach((child) ->{
      Assert.assertNull("Parent does not have and id assigned after persist it", child.getChildId());
    });

  }

在sping boot jpa存储库中是否保留嵌入式（相关）项目？

1 个答案: