ReferenceError: Cannot access module before initialization

Question

我已经创建了我的模型'order' 我尝试向 mongodb 添加新订单，但一直显示此错误，请帮助我！谢谢我依靠 add_order.ejs 来提交表单。 “ReferenceError：初始化前无法访问 'order'” 我有另外两个模型 'recipe' 和 'customer'，但它们有效！我不明白为什么只有订单有误？ order.js

const userSchema = new mongoose.Schema({
    order_id :{
        type: String,required : true
    },
    sum :{
        type:Number,
        required : true,
    },
    account :{
        type :String,
        required : true,
    }
});
module.exports = mongoose.model('order',userSchema);

routes.js

const express = require('express');
const mongoose = require('mongoose');
const router = express.Router();
const customer = require('../models/customer');
const recipe = require('../models/recipe');
const multer = require('multer');
const { GridFSBucketReadStream } = require('mongodb');
const fs = require('fs');
const order = require('../models/order');

//insert an order into database route
router.post('/add_order', upload, (req,res) => {
    const order = new order({
        order_id : req.body.order_id,
        sum : req.body.sum,
        account : req.body.account,
    });
    order.save((err) => {
        if(err){
            res.json({message : err.message, type :'danger'});
        } 
        else{
            req.session.message={
                type:'success',
                message :'Customer added successfully!'
            };
            res.redirect("/");
        }
    })
})

add_order.ejs

      <form action="/add_order" method="POST" id="add-form" enctype="multipart/form-data">
        <div class="one_third first">
          <label for="name">order_id <span>*</span></label>
          <input type="text" name="order_id" placeholder="Enter order_id" size="22" required /></td>
        </div>
        <div class="one_third">
          <label for="email">sum <span>*</span></label>
          <input type="number" name="sum" placeholder="Enter sum"  size="22" required>
        </div>
        <div class="one_third">
          <label for="url">account <span>*</span></label>
          <input type="text" name="account" placeholder="Enter account" size="22" required />
        </div>
          <input type="submit" name="submit" value="Add order" />
          <input type="reset" name="reset" value="Reset Form">
       </form>

Answer 1

你对此有疑问：

const order = require('../models/order');

//insert an order into database route
router.post('/add_order', upload, (req,res) => {
    c**onst order = new order**({ // <- you trying to change an immutable class definition

Class变量和实例变量需要有不同的名称。

建议您将 class 名称更改为 Order（大写 O）： const Order = require('../models/order');

然后像这样调用您的实例： const order = new Order({ ... });

ReferenceError: Cannot access module before initialization

ReferenceError: Cannot access module before initialization

javascript

model

mongoose

mongodb

node.js