如何使用 mongooose(v 6.8.4) 连接 index.js 和 mongodb

Question

• 首先我安装了 mongoose
• 然后我配置了 mongoose 以检查我是否可以在一个终端中连接到数据库运行 mongod 在另一个终端中运行 mongoose
• 之后我检查了它并成功连接
• 我试图连接 index.js 和 mongodb
• 我尝试连接到 mongodb 但失败了
• 这是我的代码
• 我的 index.js 文件和我有两个路由端点

const express = require('express');
const productsRouter = require("./routes/products");
const usersRouter = require("./routes/users");
const app = express();
const mongoose = require("mongoose");
mongoose.connect("mongodb://localhost:27017", {
    useNewUrlParser : true,
    useUnifiedTopology : true
}, (err) => {
    if(err){
        console.log(err);
    }
    else
        console.log("connected to MongoDB");
}); // connect method is running based on url on dbURL
app.use('/products',productsRouter);
app.use('/users',usersRouter);
app.listen(1212,()=>{
    console.log("Server is running");
});

• 这是我尝试运行 nodemon index.js 时遇到的错误

PS C:\Users\Nile-Tech\3D Objects\project\Express JS> nodemon index.js
[nodemon] 2.0.20
[nodemon] to restart at any time, enter `rs`
[nodemon] watching path(s): *.*
[nodemon] watching extensions: js,mjs,json
[nodemon] starting `node index.js`
(node:10160) [MONGOOSE] DeprecationWarning: Mongoose: the `strictQuery` option will be switched back to `false` by default in Mongoose 7. Use `mongoose.set('strictQuery', false);` if you want to prepare for this change. Or use `mongoose.set('strictQuery', true);` to suppress this warning.
(Use `node --trace-deprecation ...` to show where the warning was created)
Server is running
MongooseServerSelectionError: connect ECONNREFUSED ::1:27017
    at Connection.openUri (C:\Users\Nile-Tech\3D Objects\project\Express JS\node_modules\mongoose\lib\connection.js:825:32)
    at C:\Users\Nile-Tech\3D Objects\project\Express JS\node_modules\mongoose\lib\index.js:409:10
    at promiseOrCallback (C:\Users\Nile-Tech\3D Objects\project\Express JS\node_modules\mongoose\lib\helpers\promiseOrCallback.js:11:14)
    at Mongoose._promiseOrCallback (C:\Users\Nile-Tech\3D Objects\project\Express JS\node_modules\mongoose\lib\index.js:1262:10)        
    at Mongoose.connect (C:\Users\Nile-Tech\3D Objects\project\Express JS\node_modules\mongoose\lib\index.js:408:20)
    at Object.<anonymous> (C:\Users\Nile-Tech\3D Objects\project\Express JS\index.js:12:10)
    at Module._compile (node:internal/modules/cjs/loader:1159:14)
    at Module._extensions..js (node:internal/modules/cjs/loader:1213:10)
    at Module.load (node:internal/modules/cjs/loader:1037:32)
    at Module._load (node:internal/modules/cjs/loader:878:12) {
  reason: TopologyDescription {
    type: 'Unknown',
    servers: Map(1) { 'localhost:27017' => [ServerDescription] },
    stale: false,
    compatible: true,
    heartbeatFrequencyMS: 10000,
    localThresholdMS: 15,
    setName: null,
    maxElectionId: null,
    maxSetVersion: null,
    commonWireVersion: 0,
    logicalSessionTimeoutMinutes: null
  },
  code: undefined
}

Answer 1

可以通过将 uri localhost 更改为 127.0.0.1 来解决此错误

mongoose.connect("mongodb://127.0.0.1:27017", {
    useNewUrlParser : true,
    useUnifiedTopology : true
}, (err) => {
    if(err){
        console.log(err);
    }
    else
        console.log("connected to MongoDB");
});