sequelize 定义关联时出错答案

【问题标题】：sequelize get error when defining associationsequelize 定义关联时出错
【发布时间】：2021-05-12 02:34:53
【问题描述】：

我试图定义 sequelize 关联，但在定义 hasMany 关系时出错

error throw new Error(${this.name}.hasMany called with something that's not a subclass of Sequelize.Model);

account 和 account_type where 之间的一对多关系

account_type has many account
account belongs to account_type

这是我的代码

models/account.js

const Sequelize = require('sequelize');
const sequelize = require('../../helper/dbConnection');

const accountType = require('./accountType');

const account = sequelize.define('account', {
  id: {
    primaryKey: true,
    allowNull: true,
    autoIncrement: true,
    type: Sequelize. INTEGER,
  },
  account: {
    allowNull: false,
    unique: true,
    type: Sequelize.STRING
  },
  nominal: {
    allowNull: false,
    type: Sequelize.DOUBLE,
  }, 
  description: {
    allowNull: true,
    type: Sequelize.TEXT,
  }, 
  type_id: {
    allowNull: false,
    type: Sequelize.INTEGER,
    references: {
      model: 'account_type',
      key: 'id'
    },
    onUpdate: 'cascade',
    onDelete: 'cascade'
  },
  is_deleted: {
    allowNull: false,
    default: false,
    type: Sequelize.BOOLEAN,
  },
  created_at: Sequelize.DATE,
  updated_at: Sequelize.DATE,
});

account.belongsTo(accountType, { foreignKey: 'type_id' });

module.exports = account;

models/accountType.js

const Sequelize = require('sequelize');
const sequelize = require('../../helper/dbConnection');

const account = require('./account');

const accountType = sequelize.define('account_type', {
  id: {
    allowNull: false,
    autoIncrement: true,
    primaryKey: true,
    type: Sequelize.INTEGER
  },
  type: {
    allowNull: false,
    unique: true,
    type: Sequelize.STRING,
  },
  description: {
    allowNull: true,
    type: Sequelize.TEXT
  },
  parent_id: {
    allowNull: true,
    type: Sequelize.INTEGER,
    references: {
      model: 'account_type',
      key: 'id'
    },
    onUpdate: 'cascade',
    onDelete: 'cascade'
  },
  created_at: Sequelize.DATE,
  updated_at: Sequelize.DATE,
});

accountType.hasMany(account);

module.exports = accountType;

我已经尝试按照文档进行操作，但出现错误，我真的卡住了，请任何人帮助我

【问题讨论】：

这样的循环依赖并不理想。 account 需要 accountType 需要 account 需要 accountType...
啊，非常感谢先生，现在我知道解决方案了

标签： javascript node.js sequelize.js mysql2 sequelize-cli

【解决方案1】：

感谢ankh先生，这段代码存在循环依赖问题

解决方案只是在 1 个文件中定义关联，在 models/account.js 或 models/accountType.js

【讨论】：