我有2个实体:User和UsersList。休眠@ManyToMany删除关系
@Entity
@Table(name = "USERS")
public class User {
@Id
@GeneratedValue
@Column(name = "ID")
private Long id;
@ManyToMany(cascade = CascadeType.REMOVE, mappedBy = "users")
private List<UsersList> usersLists = new ArrayList<UsersList>();
public List<UsersList> getUsersLists() {
return usersLists;
}
public void setUsersLists(List<UsersList> usersLists) {
this.usersLists = usersLists;
}
}
和
@Entity
@Table(name = "USERS_LIST")
public class UsersList {
@Id
@GeneratedValue
@Column(name = "ID")
private Long id;
@ManyToMany
private List<User> users = new ArrayList<User>();
public List<User> getUsers() {
return users;
}
public void setUsers(List<User> users) {
this.users = users;
}
}
和这样的代码之一:
// 1
List<User> dbUsers; // 3 the user instances are persisted in DB
UsersList usersList = new UsersList();
usersList.setUsers(dbUsers);
// 2 - now persist the usersList using hibernate...
saveWithHibernate(usersList);
//3 - delete using a persisted user
deleteWithHibernate(dbUsers.get(0).getId());
其中
deleteWithHibernate(Long id) {
User usr = hibernateTemplate.get(User.class, id);
hibernateTemplate.delete(usr);
}
在步骤1我在USERS 3行(USER_ID)表。我在USERS_LIST(USERS_LIST_ID)表中有1行,并在连接表USERS_LIST_USERS(USER_ID,USERS_LIST_ID)3行中有1行。
我想在第3步中实现的是如下:当我从表中删除一个用户USERS - 假设USER_ID = 4的用户,我只想从联接表删除USER_ID = 4的行,其他人留下。
有没有注解解决我的问题?
deleteWithHibernate看起来像什么方法? – 2009-08-19 12:00:37