node.js - NodeJs : Sequelize (Version - 5+) N:M association is not working

Question

我遇到了一个与 N:M 关联与 sequelize 相关的问题。
我尝试了 5 种不同的方法(参见 User.ts & Batch.ts [1]/[2]... 的代码部分)。
请在下面找到错误和代码详细信息。

使用的版本 - "sequelize": "^5.21.5"

引用:https://sequelize.org/v5/manual/associations.html#belongs-to-many-associations

我需要你的指导来解决这个问题。

低于错误

/home/priyabrata/projects/node_backend_new/node_modules/sequelize/lib/associations/mixin.js:49
      throw new Error(`${this.name}.belongsToMany called with something that's not a subclass of Sequelize.Model`);
      ^

Error: Batch.belongsToMany called with something that's not a subclass of Sequelize.Model
    at Function.belongsToMany (/home/priyabrata/projects/node_backend_new/node_modules/sequelize/lib/associations/mixin.js:49:13)

找到下面的代码

//模型/数据库.ts

import {Sequelize} from 'sequelize';
import Config from "config";
export const database = new Sequelize(
                            Config.get("DB.NAME"), 
                            Config.get("DB.USER"), 
                            Config.get("DB.PASS"),
                            {
                                host: Config.get("DB.HOST"),
                                port: 3306,
                                dialect: 'mysql'
                            });

//模型/User.ts

import { Model, DataTypes } from "sequelize";
import { database } from "./database";
import { Batch } from "./Batch"
import { UserBatch } from "./UserBatch";

export class User extends Model {

}

export interface UserInterface {
  id: number;
  firstname: string;
  lastname: string;
}

User.init(
  {
    id: {
      type: DataTypes.INTEGER.UNSIGNED,
      autoIncrement: true,
      primaryKey: true,
      allowNull: false
    },
    firstname: {
      type: DataTypes.STRING(100),
      allowNull: false,
      defaultValue: ''
    },
    lastname: {
      type: DataTypes.STRING(100),
      allowNull: false,
      defaultValue: ''
    }
  },
  {
    underscored: true,
    tableName: "user",
    collate: "utf8mb4_unicode_ci",
    charset : "utf8mb4",
    engine : "InnoDB",
    sequelize: database, // this bit is important
    timestamps: false
  }
);



//[1] - Not working
// User.belongsToMany(Batch, {through:{model:UserBatch}, foreignKey:"user_id"});

//[2] - Not working
// User.belongsToMany(Batch, {through:{model:UserBatch}, foreignKey:"id"});

//[3] - Not working
//User.belongsToMany(Batch, {through:{model:UserBatch}, foreignKey:"id", otherKey: "user_id"});

//[4] - Not working
// User.belongsToMany(Batch, {through:'user_batch', foreignKey:"id"});

//[5] - Not working
// User.belongsToMany(Batch, {through:'user_batch', foreignKey:"id", otherKey: "user_id"});

// Below line will create table based on the above defination
// User.sync({ force: true }).then(() => console.log("User table created"));

//模型/Batch.ts

import { Model, DataTypes } from "sequelize";
import { database } from "./database";
import { User } from "./User"
import { UserBatch } from "./UserBatch"

export class Batch extends Model {
}

export interface BatchInterface {
  id: number;
  name: string;
}


Batch.init(
  {
    id: {
      type: DataTypes.INTEGER.UNSIGNED,
      autoIncrement: true,
      primaryKey: true,
      allowNull: false
    },
    name: {
      type: DataTypes.STRING(100),
      allowNull: false,
      defaultValue: ''
    }
  },  {
    underscored: true,
    tableName: "batch",
    collate: "utf8mb4_unicode_ci",
    charset : "utf8mb4",
    engine : "InnoDB",
    sequelize: database, // this bit is important
    timestamps: false
  }
);

//[1] - Not working
// Batch.belongsToMany(User, {through:{model: UserBatch}, foreignKey:"batch_id"});

//[2] - Not working
// Batch.belongsToMany(User, {through:{model: UserBatch}, foreignKey:"id"});

//[3] - Not working
//Batch.belongsToMany(User, {through:{model: UserBatch}, foreignKey:"id", otherKey: "batch_id"});

//[4] - Not working
// Batch.belongsToMany(User, {through:'user_batch', foreignKey:"id"});

//[5] - Not working
// Batch.belongsToMany(User, {through:'user_batch', foreignKey:"id", otherKey: "batch_id"});

// Below line will create table based on the above defination
// Batch.sync({ force: true }).then(() => console.log("batch table created"));

//模型/UserBatch.ts

import { Model, DataTypes } from "sequelize";
import { database } from "./database";

export class UserBatch extends Model {

}

export interface UserBatchInterface {
  user_id: number;
  batch_id: number;
}

UserBatch.init(
  {
    user_id: {
      type: DataTypes.INTEGER.UNSIGNED,
      allowNull: false
    },
    batch_id: {
      type: DataTypes.INTEGER.UNSIGNED,
      allowNull: false
    }
  },  {
    underscored: true,
    tableName: "user_batch",
    collate: "utf8mb4_unicode_ci",
    charset : "utf8mb4",
    engine : "InnoDB",
    sequelize: database, // this bit is important
    timestamps: false
  }
);

// Below line will create table based on the above defination
// UserBatch.sync({ force: true }).then(() => console.log("user_batch table created"));

Answer 1

你在某处运行这样的东西吗？？您似乎正在使用类而不是 Sequelize 模型..因此错误“用不是 Sequelize.Model 的子类的东西调用”

import { Sequelize } from 'sequelize';
import database from 'wherever that is exported';

const models = {
  User: database.import('path to where this class is'),
  UserBatch : database.import('path to where this class is'),
  Batch : database.import('path to where this class is'),
};

Object.keys(models).forEach((modelName) => {
  if ('associate' in models[modelName]) {
    models[modelName].associate(models);
  }
});

models.database= database;
models.Sequelize = Sequelize;

export default models;

然后在每个类中你可能有一个函数，上面的代码用来初始化你的类

User.associate = function (models) {
    models.User.belongsToMany(models.Batch, { through: models.UserBatch, as: 'batch', foreignKey: 'user_id' });    
  };

我意识到我使用了 javascript 并且语法不同，但想法是一样的