Question

我使用由nodejs制作的loginapp时遇到问题，但我不理解“删除usemongoclient”，因为我已经将其删除了！请帮助

完整的错误：

WARNING: The `useMongoClient` option is no longer necessary in mongoose 5.x, please remove it.
    at handleUseMongoClient (C:\Users\Corentin\node_modules\mongoose\lib\connection.js:610:17)
    at NativeConnection.Connection.openUri (C:\Users\Corentin\node_modules\mongoose\lib\connection.js:480:7)
    at Mongoose.connect (C:\Users\Corentin\node_modules\mongoose\lib\index.js:271:15)
    at Object.<anonymous> (C:\Users\Corentin\Documents\newLoginapp\models\user.js:3:10)
    at Module._compile (internal/modules/cjs/loader.js:689:30)
    at Object.Module._extensions..js (internal/modules/cjs/loader.js:700:10)
    at Module.load (internal/modules/cjs/loader.js:599:32)
    at tryModuleLoad (internal/modules/cjs/loader.js:538:12)
    at Function.Module._load (internal/modules/cjs/loader.js:530:3)
    at Module.require (internal/modules/cjs/loader.js:637:17)
    at require (internal/modules/cjs/helpers.js:22:18)
    at Object.<anonymous> (C:\Users\Corentin\Documents\newLoginapp\routes\users.js:6:12)
    at Module._compile (internal/modules/cjs/loader.js:689:30)
    at Object.Module._extensions..js (internal/modules/cjs/loader.js:700:10)
    at Module.load (internal/modules/cjs/loader.js:599:32)
    at tryModuleLoad (internal/modules/cjs/loader.js:538:12)
(node:15100) DeprecationWarning: current URL string parser is deprecated, and will be
removed in a future version. To use the new parser, pass option { useNewUrlParser: true } to MongoClient.connect.
Server started on port 3000
(node:15100) DeprecationWarning: collection.ensureIndex is deprecated. Use createIndexes instead.

这是我的代码：（不完整）要求提供更多代码

const express = require('express');
const path = require('path');
const cookieParser = require('cookie-parser');
const bodyParser = require('body-parser');
const exphbs = require('express-handlebars');
const expressValidator = require('express-validator');
const flash = require('connect-flash');
const session = require('express-session');
const passport = require('passport');
const LocalStrategy = require('passport-local').Strategy;
const mongo = require('mongodb');
const mongoose = require('mongoose');

mongoose.Promise = global.Promise;

mongoose.connect('mongodb://localhost/tuto', { useNewUrlParser: true })

var db = mongoose.connection;

const routes = require('./routes/index');
const users = require('./routes/users');

const app = express();

但是后端系统运行良好，我听不懂！ ;'（

Answer 1

//Connect to mongoose (
mongoose.connect(db.mongoURI, {

     useNewUrlParser: true    //add it
    //useMongoClient: true //old

})
.then(() => console.log('Veri baglantisi saglandi...'))
.catch(err =>console.log(err));

Answer 2

只需删除或更换

useMongoClient: true //remove it

从数据库配置文件中删除，因为当前的猫鼬版本不支持此功能，只需在数据库配置文件中添加以下代码

useNewUrlParser: true    //add it

示例

//Connect to mongoose 
   exports.connect = () => {
  mongoose.connect(mongo.uri,{
    keepAlive: 1,
    useNewUrlParser: true,
  });
  return mongoose.connection;
};

Answer 3

由于5.x猫鼬不再需要'useMongoClient'。删除后，您必须按以下方式使用新的解析器，

对于新的URL解析器，请通过选项

'useNewUrlParser: true'

对于新的服务器发现和监视引擎，请通过选项

' useUnifiedTopology: true '

最终代码部分看起来像

mongoose.connect(
    'mongodb://localhost/tuto',
    {
        // useMongoClient: true // old parameter
        useNewUrlParser: true, // new parameters
        useUnifiedTopology: true
    }
);

希望它对最新的猫鼬版本更有帮助，例如：5.8.9。

Answer 4

出现此警告是因为useMongoClient选项不再支持猫鼬新版本（> 5.x）。

解决方案已删除

useMongoClient: true //remove this code

并替换为

useNewUrlParser: true //add this code

示例

mongoose.connect('<<your uri>>', {
// useMongoClient: true
useNewUrlParser: true

}）;

如何解决“警告：在mongoose 5.x中不再需要`useMongoClient`选项，请删除它。”

4 个答案: