hibernate - Grails 映射问题 - 多对多

Question

我有以下结构

class User{
  List<Post> posts = new ArrayList<Post>();
  static hasMany = [posts: Post]
}

   class Post{
     User user  
     List<User> subscribers = new ArrayList<User>();
     static belongsTo = [user: User]
     static hasMany = [subscribers: User]
   } 

它显示

Caused by: org.codehaus.groovy.grails.exceptions.GrailsDomainException: No owner defined between domain classes [class User] and [class Post] in a many-to-many relationship. Example: static belongsTo = Post

一个用户可以有多个帖子

帖子属于用户

一个帖子可以有多个订阅者

版本 Grails 1.3.7

Answer 1

我遇到了同样的问题，这意味着在相同的两个类之间创建多对多关系和一对多关系。

这样做的方法如下:

用户类别:

class User{

  static hasMany = [createdPosts: Post, subscribedToPosts : Post]
  static mappedBy = [createdPosts : "creator"]
}

岗位类别:

class Post{  

  User creator
  static hasMany = [subscribers: User]
  static belongsTo = User
}

我在 this discussion 中找到了答案