Question

所以我在我的JavaScript应用程序上使用Sequelize作为我的PostgreSQL数据库。我有4个模型（用户，帖子，喜欢和关注跟随者）。我的用户模型工作正常，它没有任何外键，所以我能够创建和查找数据没有任何问题。但是，我的Posts模型有2个外键（user_id和parent_id）。 user_id引用Users表中的主键（id），parent_id引用自身的主键（id）（Posts表）。当我尝试将数据插入Posts表时，我能够在常规字段中插入数据，但外键只是被忽略。

这是我的数据库连接：

const Sequelize = require('sequelize');
const API = require('../../client/public/config.js');
const db = new Sequelize(API.elephantSqlUrl);

db.authenticate()
  .then(() => {
    console.log('Connection has been established successfully.');
  })
  .catch((err) => {
    console.error('Unable to connect to the database:', err);
  });

module.exports = db;

这是我的用户模型：

const Sequelize = require('sequelize');
const db = require('../db.js');

const Users = db.define('users', {
  username: {
    type: Sequelize.STRING,
    unique: true
  },
  bio: Sequelize.STRING,
  profile_picture: Sequelize.STRING
});

module.exports = Users;

这是我的帖子模型：

const Sequelize = require('sequelize');
const db = require('../db.js');

const Posts = db.define('posts', {
  type: Sequelize.INTEGER,
  body: Sequelize.STRING,
  likesCount: {
    type: Sequelize.INTEGER,
    defaultValue: 0
  }
});

module.exports = Posts;

这是我定义外键并同步我的数据库的地方：

const db = require('./db.js');
const Users = require('./models/users.js');
const Posts = require('./models/posts.js');
const Likes = require('./models/likes.js');
const FollowingsFollowers = require('./models/followingsFollowers.js');

Posts.belongsTo(Users, { foreignKey: 'user_id' });
Users.hasMany(Posts, { foreignKey: 'user_id' });
Posts.belongsTo(Posts, { foreignKey: 'parent_id' });
Posts.hasMany(Posts, { foreignKey: 'parent_id' });
Likes.belongsTo(Posts, { foreignKey: 'post_id' });
Posts.hasMany(Likes, { foreignKey: 'post_id' });
Likes.belongsTo(Users, { foreignKey: 'user_id' });
Users.hasMany(Likes, { foreignKey: 'user_id' });
FollowingsFollowers.belongsTo(Users, { foreignKey: 'following_id' });
Users.hasMany(FollowingsFollowers, { foreignKey: 'following_id' });
FollowingsFollowers.belongsTo(Users, { foreignKey: 'follower_id' });
Users.hasMany(FollowingsFollowers, { foreignKey: 'follower_id' });

db.sync({ force: true })
  .then(() => {
    console.log('db synced');
  })
  .catch(() => {
    console.log('error syncing db');
  });

这是我尝试添加帖子的地方：

const addPost = (username, post) => {
  return new Promise((resolve, reject) => {
    Users.findOne({ where: { username: username } })
      .then((user) => {
        post.user_id = user.id;

        Posts.create()
          .then((created) => {
            resolve();
          });
      })
      .catch((err) => {
        reject(err);
      });
  });
};

当我使用用户名和对象调用此函数时，使用＆＃34;键入＆＃34;和＆＃34;身体＆＃34;键，一个帖子被创建。但是，帖子包含＆＃34; id＆＃34;，＆＃34; type＆＃34;，＆＃34; body＆＃34;，＆＃34; likesCount＆＃34;，＆＃34; createdAt＆＃34;，以及＆＃34; updatedAt＆＃34;领域。＆＃34; user_id＆＃34;字段永远不会被添加到那里。

Answer 1

我不知道这是否会解决您的问题，但您没有将任何参数传递给create()方法。 post对象传递给函数，使用user_id和...忽略。

不应该是这样吗？：

(...)
Posts.create(post)
(...)

Answer 2

我能够解决它。我的解决方案是在我的模型文件上添加外键关系，如下所示：

ORDER BY

然后对于我同步我的数据库的文件，这就是我要做的所有事情，如下：

const Sequelize = require('sequelize');
const Users = require('./users.js');
const db = require('../db.js');

const Posts = db.define('posts', {
  type: Sequelize.INTEGER,
  body: Sequelize.STRING,
  likesCount: {
    type: Sequelize.INTEGER,
    defaultValue: 0
  }
});

Posts.belongsTo(Users, { foreignKey: 'user_id' });
Posts.belongsTo(Posts, { foreignKey: 'parent_id' });

module.exports = Posts;

Answer 3

1. Add user_id as foreign key in posts model and other models where realtion with users required.
2.Define your Posts models as:
const Posts = db.define('posts', {
  type: Sequelize.INTEGER,
  user_id: Sequelize.INTEGER,
  body: Sequelize.STRING,
  likesCount: {
    type: Sequelize.INTEGER,
    defaultValue: 0
  }
});
3. Remove Posts.belongsTo(Posts, { foreignKey: 'parent_id' }); not required

我无法将数据插入Sequelize中的表（具体是外键）

3 个答案: