node.js - Sequelize - 如何从一个表中获取与另一表不关联的条目

Question

我使用 Sequelize 为用户评分帖子定义了三个实体:

var User = sequelize.define('User', {
  email:  {
    type: Sequelize.STRING,
    primaryKey: true
  }
});

var Post = sequelize.define('Post', {
  link: {
    type: Sequelize.STRING,
    primaryKey: true
  }
});

var Rating = sequelize.define('Rating', {
  result: Sequelize.STRING
});

Rating.belongsTo(Post);
Post.hasMany(Rating);

Rating.belongsTo(User);
User.hasMany(Rating);

用户可以对多个帖子进行评分。每个评级只属于一个用户和一个帖子。

现在我想查询给定用户所有尚未被该用户评分的帖子。我尝试了一千种方法但没有成功。知道如何在 Sequelize 中实现这一点吗？非常感谢!

Answer 1

有两种方法，要么在 Sequelize 中使用原始查询，要么通过 Sequelize 查询 -

原始 -

return Db.sequelize.query("SELECT * FROM Post P WHERE (P.id NOT IN (SELECT postId FROM Ratings R WHERE R.userId="+userId+")) ",{ type: Sequelize.QueryTypes.SELECT });

Sequelize -

return Post.findAll({
where: {
Sequelize.literal("(posts.id NOT IN (SELECT R.postId FROM Rating R WHERE R.userId="+userId+"))")
}
});