Node.js 应用程序错误：MongooseError：`openUri()` 的 `uri` 参数必须是字符串，得到“未定义”

Question

我有一个 Next.js 应用程序。 我的错误是Mongodb，一时没能解决这个问题。 这就是为什么我想问问你们。 我希望我们能解决它。 这对我来说非常重要。 首先，我会给你我的 server.js 代码，然后我会给你来自控制台的错误消息。

Server.js 文件代码：

const express = require('express')
const next = require('next')
const mongoose = require('mongoose')
require('dotenv/config')
const dev = process.env.NODE_ENV !== 'production'

const app = next({ dev })
const handle = app.getRequestHandler()
const port = process.env.SERVER_PORT || 3000

mongoose.connect(process.env.DATABASE,{
  useNewUrlParser: true,
  useUnifiedTopology: true,
})
.then(() => {
  console.log('DB connected!')

  const port = process.env.PORT || 3000

  app.prepare().then(()=>{
    const server = express()
  
    //ROUTES
    server.use(express.json())
    server.get('*', (req, res) => handle(req, res))
  
    server.listen(port, (err) => {
      if(err) throw err
      console.log(`Server listen on http://127.0.0.1:${port}`)
    })
  
  })

})
.catch((err) => {
  console.log('DB ERROR:', err)
})

控制台上的错误消息：

DB ERROR: MongooseError: The `uri` parameter to `openUri()` must be a string, got "undefined". Make sure the first parameter to `mongoose.connect()` or `mongoose.createConnection()` is a string.
    at NativeConnection.Connection.openUri (/home/ubuntu/nodeApps/mywebsite-next/node_modules/mongoose/lib/connection.js:684:11)
    at /home/ubuntu/nodeApps/mywebsite-next/node_modules/mongoose/lib/index.js:332:10
    at /home/ubuntu/nodeApps/mywebsite-next/node_modules/mongoose/lib/helpers/promiseOrCallback.js:32:5
    at new Promise (<anonymous>)
    at promiseOrCallback (/home/ubuntu/nodeApps/mywebsite-next/node_modules/mongoose/lib/helpers/promiseOrCallback.js:31:10)
    at Mongoose._promiseOrCallback (/home/ubuntu/nodeApps/mywebsite-next/node_modules/mongoose/lib/index.js:1158:10)
    at Mongoose.connect (/home/ubuntu/nodeApps/mywebsite-next/node_modules/mongoose/lib/index.js:331:20)
    at Object.<anonymous> (/home/ubuntu/nodeApps/mywebsite-next/server.js:11:10)
    at Module._compile (node:internal/modules/cjs/loader:1101:14)
    at Object.Module._extensions..js (node:internal/modules/cjs/loader:1153:10)

我的 env 文件中有 Mongodb 的链接。 也许错误是由于这种情况引起的？

DATABASE=mongodb+srv://myusername:mypassword@cluster0.u4slu.mongodb.net/mydbusername?retryWrites=true&w=majority

Answer 1

您应该将您的登录凭据放入您的 mongodb url 代码中，如下所示：

DATABASE=mongodb+srv://admin:admin@cluster0.u4slu.mongodb.net/<dbusername>?retryWrites=true&w=majority

如果您已经尝试给出 dotenv 的路径：

require('dotenv').config({ path: 'ENV_FILENAME' });

Answer 2

mongoose.connect(`${process.env.DATABASE}`, () => {
  console.log('database connected successfully');
})