我有一个数据库包装类，建立一个连接到一些MongoDB实例:
async connect(connectionString: string): Promise<void> {
this.client = await MongoClient.connect(connectionString)
this.db = this.client.db()
}
这给了我一个警告:
(node:4833) DeprecationWarning:当前URL字符串解析器已弃用，并将在未来版本中删除。要使用新的解析器，将选项{useNewUrlParser: true}传递给MongoClient.connect。
connect()方法接受一个MongoClientOptions实例作为第二个参数。但它没有useNewUrlParser属性。我还尝试在连接字符串中设置这些属性，就像这样:mongodb://127.0.0.1/my-db?useNewUrlParser=true，但它对那些警告没有影响。
那么我怎么能设置useneurlparser删除这些警告?这对我来说很重要，因为脚本应该以cron的方式运行，而这些警告会导致垃圾邮件。
我使用3.1.0-beta4版本的mongodb驱动程序，并在3.0.18中使用相应的@types/mongodb包。它们都是npm install可用的最新版本。
解决方案
使用旧版本的mongodb驱动程序:
"mongodb": "~3.0.8",
"@types/mongodb": "~3.0.18"
我使用mlab.com作为MongoDB数据库。我将连接字符串分离到一个名为config的不同文件夹，并在文件keys.js中保存连接字符串，这是:
模块导出 = {
mongoURI：“mongodb://username:password@ds147267.mlab.com:47267/projectname”
};
服务器代码是
const express = require("express");
const mongoose = require("mongoose");
const app = express();
// Database configuration
const db = require("./config/keys").mongoURI;
// Connect to MongoDB
mongoose
.connect(
db,
{ useNewUrlParser: true } // Need this for API support
)
.then(() => console.log("MongoDB connected"))
.catch(err => console.log(err));
app.get("/", (req, res) => res.send("hello!!"));
const port = process.env.PORT || 5000;
app.listen(port, () => console.log(`Server running on port ${port}`)); // Tilde, not inverted comma
你需要像上面那样在连接字符串后面写{useNewUrlParser: true}。
简单地说，你需要做到:
猫鼬。connect(connectionString，{useNewUrlParser: true}
/ /或
MongoClient。connect(connectionString，{useNewUrlParser: true}
(node:16596) 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.
(Use node --trace-deprecation ... to show where the warning was
created) (node:16596) [MONGODB DRIVER] Warning: Current Server
Discovery and Monitoring engine is deprecated, and will be removed in
a future version. To use the new Server Discover and Monitoring
engine, pass option { useUnifiedTopology: true } to the MongoClient
constructor.
用法:
async connect(connectionString: string): Promise<void> {
this.client = await MongoClient.connect(connectionString, {
useUnifiedTopology: true,
useNewUrlParser: true,
})
this.db = this.client.db()
}
Express.js、API调用case和发送JSON内容的完整示例如下:
...
app.get('/api/myApi', (req, res) => {
MongoClient.connect('mongodb://user:password@domain.com:port/dbname',
{ useNewUrlParser: true }, (err, db) => {
if (err) throw err
const dbo = db.db('dbname')
dbo.collection('myCollection')
.find({}, { _id: 0 })
.sort({ _id: -1 })
.toArray(
(errFind, result) => {
if (errFind) throw errFind
const resultJson = JSON.stringify(result)
console.log('find:', resultJson)
res.send(resultJson)
db.close()
},
)
})
}
