javascript - 为什么在将用户输入数据库时​​出现错误？

Question

我正在自学Mongodb。首先，我在 Terminal 中运行 npm install --save mongoose uuid 来开始操作。我的程序的目标是将用户存储在数据库中。

在终端中，运行node index.js后，我想说:

About to save!
Saved!

但是我在Terminal中看到的是(如下):

这是index.js

var mongoose = require('mongoose');
var uuid = require('uuid');

var Schema = mongoose.Schema;


/* New code from suggested website in error */ 

var promise = mongoose.connect('mongodb://localhost:testMongo/testMongo', {
    useMongoClient: true,
});

promise.then(function(db) {

    db.model();
    connection.openUri('mongodb://localhost:testMongo/testMongo', { /* options */ });


var userSchema = new Schema({
    email: {
        type: String,
        unique: true
    },
    password: {type: String},

    todos: [
        {
            text: {type: String}
        }
    ]
});

userSchema.pre('save', function(next) {
    console.log("About to save!");
    var user = this;
    user.password = uuid.v4();
    next();
});

 var User = mongoose.model('user', userSchema);
 var email = 'test@test.com';

// var user = new User({
//     email: email
// });
//
// user.save(function(err) {
//     if(err) {
//         return console.log(err);
//     } else {
//         return console.log("User was saved!");
//     }
// })
//
// console.log("Outside of callback!");

var text = "This is a todo.";

User.findOne({email: email}, function(user, err) {
   if(err) {
       return console.log(err);
   }

   if(!user) {
       return console.log("Couldn't find user!");
   }

   var count = user.todos.push({
       text: text
   });

   console.log(count);

   user.save(function(err){
      if(err) {
          console.log(err);
      } else {
          console.log("Saved!");
      }
   });
});

终端中出现错误:

(node:14312) DeprecationWarning: `open()` is deprecated in mongoose >= 4.11.0, use `openUri()` instead, or set the `useMongoClient` option if using `connect()` or `createConnection()`. See http://mongoosejs.com/docs/connections.html#use-mongo-client
{ _id: 595fe7c14a9810330c75aacc,
  password: '297d5907-d9d7-49ef-800c-97a56aa395f7',
  email: 'test@test.com',
  __v: 0,
  todos: [] }

Answer 1

这不是一个错误。它清楚地表明这是一个警告:DeprecationWarning。该消息还为您提供了解决警告的链接: http://mongoosejs.com/docs/connections.html#use-mongo-client