javascript - TypeError : callback. apply is not a function (Node.js & Mongodb)

Question

当我添加“{ upsert: true }”行时，我收到了这个错误:

TypeError: callback.apply 不是函数

// on routes that end in /users/competitorAnalysisTextData
// ----------------------------------------------------

router
  .route('/users/competitorAnalysisTextData/:userName')

  // update the user info (accessed at PUT http://localhost:8080/api/users/competitorAnalysisTextData)
  .post(function (req, res) {
    // use our user model to find the user we want
    User.findOne({userName: req.params.userName}, function (err, user) {
      if (err) res.send(err);

      console.log(
        'user.competitorAnalysis.firstObservation: %@',
        user.competitorAnalysis.firstObservation,
      );
      // Got the user name
      var userName = user.userName;
      // update the text data
      console.log('Baobao is here!');
      user.update(
        {
          userName: userName,
        },
        {
          $set: {
            'competitorAnalysis.firstObservation': req.body.firstObservation,
            'competitorAnalysis.secondObservation': req.body.secondObservation,
            'competitorAnalysis.thirdObservation': req.body.thirdObservation,
            'competitorAnalysis.brandName': req.body.brandName,
            'competitorAnalysis.productCategory': req.body.productCategory,
          },
        },
        {upsert: true},
      );

      // save the user
      user.save(function (err) {
        if (err) return res.send(err);

        return res.json({message: 'User updated!'});
      });
    });
  });

没有这一行，就没有错误。我是nodejs新手，不太清楚问题出在哪里。

更新

现在没有错误消息，但是这部分数据库没有用新数据更新。嵌入的文档仍然是空的。

// on routes that end in /users/competitorAnalysisTextData
// ----------------------------------------------------
router
  .route('/users/competitorAnalysisTextData/:userName')

  // update the user info (accessed at PUT http://localhost:8080/api/users/competitorAnalysisTextData)
  .post(function (req, res) {
    console.log('1');

    // Just give instruction to mongodb to find document, change it;
    // then finally after mongodb is done, return the result/error as callback.
    User.findOneAndUpdate(
      {userName: req.params.userName},
      {
        $set: {
          'competitorAnalysis.firstObservation': req.body.firstObservation,
          'competitorAnalysis.secondObservation': req.body.secondObservation,
          'competitorAnalysis.thirdObservation': req.body.thirdObservation,
          'competitorAnalysis.brandName': req.body.brandName,
          'competitorAnalysis.productCategory': req.body.productCategory,
        },
      },
      {upsert: true},
      function (err, user) {
        // after mongodb is done updating, you are receiving the updated file as callback
        console.log('2');
        // now you can send the error or updated file to client
        if (err) return res.send(err);

        return res.json({message: 'User updated!'});
      },
    );
  });

Answer 1

在 mongodb 中更新文档有两种方式:

1. 找到文档，将其带到服务器，更改它，然后将其保存回 mongodb。

2. 只要指示mongodb查找文件，修改即可；然后最后在mongodb完成后，将结果/错误作为回调返回。

在您的代码中，您正在混合使用这两种方法。

---

1. 使用 user.save()，首先你使用 user.findOne 搜索数据库，然后将其拉到 server(nodejs)，现在它存在于你的计算机内存中。然后您可以手动更改数据，最后使用 user.save() 将其保存到 mongodb

   User.findOne({ userName: req.params.userName}, function(err, user) {
   
       if (err)
           res.send(err);
   
       //this user now lives in your memory, you can manually edit it
       user.username = "somename";
       user.competitorAnalysis.firstObservation = "somethingelse";
   
       // after you finish editing, you can save it to database or send it to client
        user.save(function(err) {
           if (err)
               return res.send(err);
   
           return res.json({ message: 'User updated!' });
       });
   

2. 第二个是使用 User.findOneAndUpdate().. 这是首选，而不是 user.findOne() 然后 user.update();因为那些基本上搜索数据库两次。先到 findOne()，再搜索到 update()

无论如何，第二种方法是告诉 mongodb 更新数据而不先带入服务器，接下来，只有在 mongodb 完成其操作后，您才会收到更新的文件(或错误)作为回调

User.findOneAndUpdate({ userName: req.params.userName}, 
            {
             $set: { "competitorAnalysis.firstObservation" : req.body.firstObservation,
                      "competitorAnalysis.secondObservation" : req.body.secondObservation,
                      "competitorAnalysis.thirdObservation" : req.body.thirdObservation,
                      "competitorAnalysis.brandName" : req.body.brandName,
                      "competitorAnalysis.productCategory" : req.body.productCategory
            } },
            { upsert: true },
        function(err, user) {
        //after mongodb is done updating, you are receiving the updated file as callback    

        // now you can send the error or updated file to client
        if (err)
            res.send(err);

        return res.json({ message: 'User updated!' });
        });