node.js - 类型错误：db.model 不是函数

Question

node 和 mongodb 的新手 我正在开发一个 linux Centos 7 环境。 出于某种原因，我收到此错误“TypeError: db.model is not a function”

这个错误是什么意思？

    /var/www/html/mongo/crud/src/model/task.js:11
    return db.model('tasks',Task);
              ^

TypeError: db.model is not a function
    at module.exports (/var/www/html/mongo/crud/src/model/task.js:11:15)
    at Object.<anonymous> (/var/www/html/mongo/crud/src/routes/index.js:4:39)
    at Module._compile (module.js:570:32)
    at Object.Module._extensions..js (module.js:579:10)
    at Module.load (module.js:487:32)
    at tryModuleLoad (module.js:446:12)
    at Function.Module._load (module.js:438:3)
    at Module.require (module.js:497:17)
    at require (internal/module.js:20:19)
    at Object.<anonymous> (/var/www/html/mongo/crud/src/app.js:9:21)
    at Module._compile (module.js:570:32)
    at Object.Module._extensions..js (module.js:579:10)
    at Module.load (module.js:487:32)
    at tryModuleLoad (module.js:446:12)
    at Function.Module._load (module.js:438:3)
    at Module.runMain (module.js:604:10)
[nodemon] app crashed - waiting for file changes before starting...

这是task.js文件的内容：

module.exports = function(){

    var db = require('../libs/db-connection')();
    var Schema = require('mongoose').Schema;

    var Task = Schema({
        title: String,
        description: String,
        status: Boolean
    });
    return db.model('tasks',Task);
}

这是 index.js 文件的内容：

const express = require('express');
const router = express.Router();

const model = require('../model/task')();

router.get('/' ,(req, res) => {
    model.find({}, (err, tasks) =>{
        if (err) throw err;
        res.render('index', {
            title: 'CRUD',
            task: tasks
        });
    });
});

module.exports = router;

Answer 1

除非您的libs/db-connection 中有model 函数，否则我认为您想使用mongoose 中的model。

如果这是正确的，要解决您的问题，您需要从 mongoose 更改导入，如下所示：

var mongoose = require('mongoose');  // Not require('mongoose').Schema (because you need schema and model)

var Task = mongoose.Schema({  // Call Schema from mongoose
    title: String,
    description: String,
    status: Boolean
});

return mongoose.model('tasks',Task);  // Call model from mongoose