Node.JS和Sequelize定义关系

有两种型号，客户和订单型号订单定义

Order.belongsTo(Customer {foreignKey: 'customer_id', as: 'customer'});

在模型Customer定义中

Customer.hasMany(Order, {foreignKey: 'customer_id', as: 'orders'});

得到了这个错误

Error: customer.hasMany called with something that's not a subclass of Sequelize.Model

....

如何定义这些没有错误？

感谢帮助

试试这个

    var config = require('../config/environment');
    var Sequelize = require('sequelize');

    var db = {
      Sequelize,
      sequelize: new Sequelize(config.mysql.uri, config.mysql.options)
    };

   db.Customer = db.sequelize.import(modal_path);  //your schema
   db.Order = db.sequelize.import(modal_path);  //your schema

   db.Customer.hasMany(db.Order, {
      foreignKey: 'customer_id'
    });

    db.Order.belongsTo(db.Customer, {
      foreignKey: 'customer_id',
      targetKey: 'Id'
    });