无法使用带有express的mongodb调用未定义的方法'get'

Question

我按照教程进行操作，但不知道出了什么问题。我的 cmd 完全没有错误。当我打开 localhost:3000 时，我看到了这个错误 Cannot call method 'get' of undefined 并且无法在我的帖子集合中加载帖子。

var express = require('express');
var router = express.Router();
var mongo = require('mongodb');
var db = require('monk')('localhost/nodeblog');

/* Homepage blog posts */
router.get('/', function(req, res, next) {
  var db = req.db;
  var posts = db.get('posts');
  console.log(posts)
  posts.find({},{},function(err,posts){
    res.render('index',{
        "posts":posts
    });
  });
});

我的玉

block content
    if posts
        each post, i in posts
            h1=post.title

Answer 1

有问题， 您需要先将 db 附加到 req 对象，然后使用它。将此功能放在所有路线之前。

app.use(function(req, res, next) {
  // open connection
  req.db = db;
  next();
});

then use it in route.

var dbs = req.db;

否则很简单，删除此行并运行您的应用程序。

var db = req.db;

完整代码

var express = require('express');
var mongo = require('mongodb');
var db = require('monk')('localhost/nodeblog');

var app = express();

app.use(function(req, res, next) {
  req.db = db;
  next();
});

app.get('/', function(req, res, next) {
  var dbPost = req.db;
  var posts = dbPost.get('posts');
  console.log(posts)
  posts.find({},{},function(err, posts){
    res.render('index',{
        posts: posts
    });
  });
});

app.listen(3000);