Sequelize.js 当关系不存在时，续写归属关系'；不要使用主键

我正在建立一个社交网络，所以我的模型是帖子、用户和用户跟踪用户关系

var User = sequelize.define('user', {
  username: Sequelize.DataTypes.STRING
})

var Post = sequelize.define('post', {
  text: Sequelize.DataTypes.STRING,
  userId: Sequelize.DataTypes.INTEGER 
})

var Follow = sequelize.define('follow', {
    followerUserId: Sequelize.DataTypes.INTEGER,
    followingUserId: Sequelize.DataTypes.INTEGER,
  })

为了获得某个用户的提要（他们跟踪的用户的所有帖子），我需要能够执行如下查询：

User.findById(13).then(user => user.getFollowingPosts())

但我被这个协会迷住了：

User.belongsToMany(Post, {
      as: 'followingPosts',
      through: { model: Follow, },
      foreignKey: 'followerUserId',
      otherKey: 'userId',
    });

生成错误的SQL连接条件，我无法修复：

SELECT ...
FROM `posts` AS `post` INNER JOIN `follows` AS `follow`
  ON `post`.`id` = `follow`.`userId` AND `follow`.`followerUserId` = 13

---

我无法将Sequelize改为userpost.userId而不是post.id

找到了一个足够好的解决方法：

Post.belongsTo(Follow, {
  as: 'following',
  foreignKey: 'userId',
  targetKey: 'followingUserId',
  allowNull: false
})

这样，我就完全跳过User.blonggasmy并查询以下信息：

Post.findAll({
  include: [{
    association: Post.associations.following,
    where: { followerUserId: 13}
  }]
})

由此产生：

SELECT ...
FROM `posts` AS `post` INNER JOIN `follows` AS `following`
  ON `post`.`userId` = `following`.`followingUserId` AND
     `following`.`followerUserId` = 13