node.js - NodeJS 无法导入 Sequelize.js 模型(ES6)

Question

我正在使用 Express 和 Seqeulize 运行 NodeJS，并且有一个文件 controllers/rooms.js 从 models/room.js 导入 Room。

import Room from '../models'

export function list(req, res) {
    return Room
        .findAll()
        .then((rooms) => res.status(200).send(rooms))
        .catch((error) => res.status(400).send(error))
}

波纹管是models/room.js(同一目录下还有sequelize-cli生成的index.js文件)

'use strict'

export default (sequelize, DataTypes) => {

    const Room = sequelize.define('Room', {
        name: DataTypes.STRING
    })

    return Room
}

我有一条路线 app.get('/rooms', list)，但是当我访问此路线时，出现此错误:

TypeError: _models2.default.findAll is not a function
    at list (/Users/matis/Documents/apps/node-docker-test/app/database/controllers/rooms.js:21:10)
    at Layer.handle [as handle_request] (/Users/matis/Documents/apps/node-docker-test/node_modules/express/lib/router/layer.js:95:5)
    at next (/Users/matis/Documents/apps/node-docker-test/node_modules/express/lib/router/route.js:137:13)
    at Route.dispatch (/Users/matis/Documents/apps/node-docker-test/node_modules/express/lib/router/route.js:112:3)
    at Layer.handle [as handle_request] (/Users/matis/Documents/apps/node-docker-test/node_modules/express/lib/router/layer.js:95:5)
    at /Users/matis/Documents/apps/node-docker-test/node_modules/express/lib/router/index.js:281:22
    at Function.process_params (/Users/matis/Documents/apps/node-docker-test/node_modules/express/lib/router/index.js:335:12)
    at next (/Users/matis/Documents/apps/node-docker-test/node_modules/express/lib/router/index.js:275:10)
    at expressInit (/Users/matis/Documents/apps/node-docker-test/node_modules/express/lib/middleware/init.js:40:5)
    at Layer.handle [as handle_request] (/Users/matis/Documents/apps/node-docker-test/node_modules/express/lib/router/layer.js:95:5)
    at trim_prefix (/Users/matis/Documents/apps/node-docker-test/node_modules/express/lib/router/index.js:317:13)
    at /Users/matis/Documents/apps/node-docker-test/node_modules/express/lib/router/index.js:284:7
    at Function.process_params (/Users/matis/Documents/apps/node-docker-test/node_modules/express/lib/router/index.js:335:12)
    at next (/Users/matis/Documents/apps/node-docker-test/node_modules/express/lib/router/index.js:275:10)
    at query (/Users/matis/Documents/apps/node-docker-test/node_modules/express/lib/middleware/query.js:45:5)
    at Layer.handle [as handle_request] (/Users/matis/Documents/apps/node-docker-test/node_modules/express/lib/router/layer.js:95:5)
    at trim_prefix (/Users/matis/Documents/apps/node-docker-test/node_modules/express/lib/router/index.js:317:13)
    at /Users/matis/Documents/apps/node-docker-test/node_modules/express/lib/router/index.js:284:7
    at Function.process_params (/Users/matis/Documents/apps/node-docker-test/node_modules/express/lib/router/index.js:335:12)
    at next (/Users/matis/Documents/apps/node-docker-test/node_modules/express/lib/router/index.js:275:10)
    at Function.handle (/Users/matis/Documents/apps/node-docker-test/node_modules/express/lib/router/index.js:174:3)
    at Function.handle (/Users/matis/Documents/apps/node-docker-test/node_modules/express/lib/application.js:174:10)

我确定我的导入/导出搞砸了，但我不知道是怎么回事。

models/index.js 文件如下

'use strict'

import { readdirSync } from 'fs'
import { basename as _basename, join } from 'path'
import Sequelize from 'sequelize'
const basename = _basename(__filename)
const env = process.env.NODE_ENV || 'development'
const config = require(__dirname + '/../config/config.json')[env]
const db = {}

let sequelize
if (config.use_env_variable) {
    sequelize = new Sequelize(process.env[config.use_env_variable], config)
} else {
    sequelize = new Sequelize(config.database, config.username, config.password, config)
}

readdirSync(__dirname)
    .filter(file => {
        return (file.indexOf('.') !== 0) && (file !== basename) && (file.slice(-3) === '.js')
    })
    .forEach(file => {
        const model = sequelize['import'](join(__dirname, file))
        db[model.name] = model
    })

Object.keys(db).forEach(modelName => {
    if (db[modelName].associate) {
        db[modelName].associate(db)
    }
})

db.sequelize = sequelize
db.Sequelize = Sequelize

export default db

当我这样调用它时它就起作用了: 返回 Room.Room.findAll()... 因此我可以将导入重命名为: 从“../models”导入模型 并这样调用它: 返回 models.Room.findAll()...

但是为什么我不能直接调用它return Room.findAll()...，导入应该如何制定？？

Answer 1

假设您已设置 babel 来使用 ES6 导入，您可以尝试使用此方法在 ES6 中导出 Sequelize 模型。

//数据库配置文件

import Sequelize from 'sequelize';

export const sequelize = new Sequelize(
  config.database.name,
  config.database.user,
  config.database.password,
  {
    host: config.database.host,
    dialect: config.database.dialect,
    pool: config.database.pool,
    operatorsAliases: false
  }
);

//模型

import Sequelize from 'sequelize';
import { sequelize } from '../database/db';

const User = sequelize.define(
  'table_name',
  {
    id: {
      type: Sequelize.INTEGER,
      primaryKey: true,
      autoIncrement: true
    },
    name: {
      type: Sequelize.STRING,
      allowNull: false
    },
    email: {
      type: Sequelize.STRING,
      allowNull: false
    },
    password: {
      type: Sequelize.STRING,
      allowNull: false
    }
  },
  { freezeTableName: true }
);

export default User;