Question

我有这个数据库结构。有一些用户每年阅读书籍，并汇编他们阅读过的书籍清单：

users       years        books----booklists
   |           |                      |
   ------------------------------------
               |      
           userlists

我有一个用户的表：

users:
+-----------+---------+
|    id     |  name   |
+-----------+---------+

@Entity
public class User  {
  @Id @GeneratedValue
  private int id;

  //?
  private List<UserList> booklists = new ArrayList<>();
}

每个用户都有他们在特定年份已阅读的图书的列表：

books:
+-----------+---------+
|    id     |  title  |
+-----------+---------+

@Entity
public class Book  {
  @Id @GeneratedValue
  private int id;
}

每个用户的列表位于 booklists 表中：

booklists:
+-----+---------+---------+
| id  | list_id | book_id |
+-----+---------+---------+

@Entity
public class BookList  {
  @Id @GeneratedValue
  private int id;

  @Column(name="list_id")
  private int listId;

  @Column(name="book_id")
  private int bookId;
}

最后，书单和用户被合并到用户列表：

years:
+-----+------+
| id  | year |
+-----+------+

userlists:
+-----+---------+---------+---------+
| id  | user_id | list_id | year_id |
+-----+---------+---------+---------+

@Entity
public class UserList  {
  @Id @GeneratedValue
  private int id;
  @Column(name="user_id")
  private int userId;
  @Column(name="list_id")
  private int listId;
  @Column(name="year_id")
  private int yearId;
}

我不确定如何在private List<UserList> booklists = new ArrayList<>();中使用User。我知道一对多可以这样映射：

@OneToMany
@JoinTable(joinColumns=@JoinColumn(name="user_id"),
           inverseJoinColumns=@JoinColumn(name="list_id")
List<UserList> booklists = new ArrayList<>();

但是我遇到的情况比我看过的任何教程都多。

Hibernate：如何从该数据库结构中获取用户的书籍清单

0 个答案: