Question

我有一个表，该表具有一个自引用联接表。

@Entity
public class Employee {
    @OneToMany(mappedBy = "employee", cascade = CascadeType.ALL, orphanRemoval = true)
    private List<EmployeeDependency> employeeDependencies;
}

@Entity
public class EmployeeDependency {
    @ManyToOne
    @JoinColumn
    private Employee employee;

    @ManyToOne
    @JoinColumn
    private Employee employeeDependency;
}

如我们所见，该关系由mappedBy = "employee"管理。 DB依赖表看起来像这样

EmployeeDependency
----------------------------------------
id employee_id employee_dependency_id
----------------------------------------
1     2         3
2     2         4
3     3         10

现在，当我尝试删除employee= 2时，它将删除EmployeeDependency表中的引用，并且还将删除Employee表中的记录，因为依赖项是由employee管理的。映射mappedBy = "employee"。这是预料之中的，并且按其编写的方式工作。

但是现在当我尝试删除关系的另一端的employee = 10时，我遇到了foreign key引用错误。

如果我在Employee实体中放置一个虚拟引用，就可以删除它

   @Entity
   public class Employee {
        @OneToMany(mappedBy = "employee", cascade = CascadeType.ALL, orphanRemoval = true)
        private List<EmployeeDependency> employeeDependencies;

        @OneToMany(mappedBy = "employeeDependency", cascade = CascadeType.ALL, orphanRemoval = true)
        private List<EmployeeDependency> dummyEmployeeDependencies;
    }

但这似乎不对！如何放置双向级联，以便可以从关系的任一侧删除ID

自引用联接表上的双向级联

0 个答案: