我有一個課程評論一對多的關系。在課程表中有 id 和 title 列。在 Review 表中有 id、comment 和 course_id，其中“course_id”作為 FK 指向 Course id。我想實現這樣的場景，一旦課程被刪除，相關的評論就會被自動刪除。我有以下代碼：@Entity@Table(name = "course")public class Course {    @Id    @GeneratedValue(strategy = GenerationType.IDENTITY)    @Column(name = "id")    private int id;    @Column(name = "title")    private String title;    @OneToMany(mappedBy = "course", fetch = FetchType.LAZY, cascade = CascadeType.ALL, orphanRemoval = true)    private List<Review> reviews;    public void addReview(Review review){        if(reviews==null) reviews = new ArrayList<>();        reviews.add(review);    }    //other codes below omitted}@Entity@Table(name = "review")public class Review {    @Id    @GeneratedValue(strategy = GenerationType.IDENTITY)    @Column(name = "id")    private int id;    @Column(name = "comment")    private String comment;    @ManyToOne(fetch = FetchType.LAZY, cascade = CascadeType.ALL)    @JoinColumn(name = "course_id")    private Course course;//other codes omitted}