Question

我在Nodejs中定义了我的API路由，但是当我运行它时，它会给出此错误消息。

错误消息

ReferenceError：未定义项目

at D:\shoppinglist\serverside\route\routes.js:7:5
at Layer.handle [as handle_request] (D:\shoppinglist\serverside\node_modules\express\lib\router\layer.js:95:5)
at next (D:\shoppinglist\serverside\node_modules\express\lib\router\route.js:137:13)
at Route.dispatch (D:\shoppinglist\serverside\node_modules\express\lib\router\route.js:112:3)
at Layer.handle [as handle_request] (D:\shoppinglist\serverside\node_modules\express\lib\router\layer.js:95:5)
at D:\shoppinglist\serverside\node_modules\express\lib\router\index.js:281:22
at Function.process_params (D:\shoppinglist\serverside\node_modules\express\lib\router\index.js:335:12)
at next (D:\shoppinglist\serverside\node_modules\express\lib\router\index.js:275:10)
at Function.handle (D:\shoppinglist\serverside\node_modules\express\lib\router\index.js:174:3)
at router (D:\shoppinglist\serverside\node_modules\express\lib\router\index.js:47:12)
at Layer.handle [as handle_request] (D:\shoppinglist\serverside\node_modules\express\lib\router\layer.js:95:5)
at trim_prefix (D:\shoppinglist\serverside\node_modules\express\lib\router\index.js:317:13)
at D:\shoppinglist\serverside\node_modules\express\lib\router\index.js:284:7
at Function.process_params (D:\shoppinglist\serverside\node_modules\express\lib\router\index.js:335:12)
at next (D:\shoppinglist\serverside\node_modules\express\lib\router\index.js:275:10)
at jsonParser (D:\shoppinglist\serverside\node_modules\body-parser\lib\types\json.js:110:7)

我的Route.js代码为

var express = require('express');

var router = express.Router();

router.get('/items', (req, res, next)=>{
    Item.find(function(err, items){
        if(err){
            res.json(err);
        }
        else{
            res.json(items);
        }
    });
});
router.post('/item', (req, res, next)=>{
    let newShoppingItem = new Item({
        itemName: req.body.itemName,
        itemQuantity: req.body.itemQuantity,
        itemBought: req.body.itemBought
    });
    newShoppingItem.save((err, item)=>{
        if(err){
            res.json(err)
        }
        else{
            res.json({msg: 'Item has been added to db'});
        }
    });
});
router.put('/put_test', (req, res, next)=>{
  // do later
});

router.delete('/delete_test', (req, res, next)=>{
  // do later
});

module.exports = router;

这是我的shoopingitem.js代码

shoppingitem.js

const mongoose = require('mongoose');

const shoppingItemSchema = mongoose.Schema({

    itemName:{
        type: String,
        require:true
    },

    itemQuantity:{
        type: Number,
        require:true
    },

    itemBought:{
        type: Boolean,
        require:true
    },

});
const Item = module.exports = mongoose.model('Item', shoppingItemSchema);

请给我建议解决方案。我是nodejs的新手。所以请帮助

预先感谢

Answer 1

您需要在路由文件中需要Item模型才能使用它。这可以通过两种方式完成：

const Item = require('../path/to/item/shoppingItem.js')

或

const mongoose = require('mongoose')
const Item = mongoose.model('Item');

Answer 2

正如Matthew Weeks所提到的，请确保将猫鼬Item模型导入到Route.js文件中。

此外，如果您要查询集合中的所有项目，请确保在查找功能中包括一个空的查询对象作为第一个参数。包括Matthew Weeks解决方案在内，Route.js的第一部分应类似于：

const Item = require('../path/to/item/shoppingItem.js');
var express = require('express');
var router = express.Router();

router.get('/items', (req, res, next)=>{
Item.find({}, function(err, items){
    if(err){
        res.json(err);
    }
    else{
        res.json(items);
    }
});

ReferenceError：在NodeJs路由中未定义项目

2 个答案: