Javascript 将mongodb连接到节点应用程序时出现连接错误

在我在端口27017启动服务器后，打开另一个窗口并运行我的服务器程序，它显示连接错误，如下所示

C:\node-mongodb\node_modules\mongodb\lib\server.js:242
process.nextTick(function() { throw err; })
                              ^
AssertionError: { [MongoError: connect UNKNOWN 127.0.0.1:27017 - 
Local(undefined:undefined)]
name: 'MongoError',
message: 'connect UNKNOWN  == null
at C:\node-mongodb\simple-server.js:8:12
at C:\node-mongodb\node_modules\mongodb\lib\mongo_client.js:330:20
at C:\node-mongodb\node_modules\mongodb\lib\db.js:231:14
at null.<anonymous> (C:\node-mongodb\node_modules\mongodb\lib\server.js:240:9)
at g (events.js:260:16)
at emitTwo (events.js:87:13)
at emit (events.js:172:7)
at null.<anonymous(C:\nodemongodb\node_modules\mongodb\node_modules\mongo
db-core\lib\topologies\server.js:218:12)
at g (events.js:260:16)
at emitTwo (events.js:87:13)

}))

C:\node-mongodb\node_modules\mongodb\lib\server.js:242
process.nextTick(function() { throw err; })
                              ^
AssertionError: { [MongoError: connect UNKNOWN 127.0.0.1:27017 - 
Local(undefined:undefined)]
name: 'MongoError',
message: 'connect UNKNOWN  == null
at C:\node-mongodb\simple-server.js:8:12
at C:\node-mongodb\node_modules\mongodb\lib\mongo_client.js:330:20
at C:\node-mongodb\node_modules\mongodb\lib\db.js:231:14
at null.<anonymous> (C:\node-mongodb\node_modules\mongodb\lib\server.js:240:9)
at g (events.js:260:16)
at emitTwo (events.js:87:13)
at emit (events.js:172:7)
at null.<anonymous(C:\nodemongodb\node_modules\mongodb\node_modules\mongo
db-core\lib\topologies\server.js:218:12)
at g (events.js:260:16)
at emitTwo (events.js:87:13)

---

命令提示的屏幕截图如下：

您能通过shell连接到mongo吗？你能在你的应用程序中发布你用来连接mongo的代码吗？你能展示你的simple-server.js并试着在cmd windows中键入mongo命令吗罗伯特：我可以使用shell连接mongo。你能通过shell连接mongo吗？你能在你的应用程序中发布你用来连接mongo的代码吗？你能显示你的simple-server.js并尝试在cmd windows中键入mongo命令吗罗伯特：我可以使用shell连接mongo。

C:\node-mongodb\node_modules\mongodb\lib\server.js:242
process.nextTick(function() { throw err; })
                              ^
AssertionError: { [MongoError: connect UNKNOWN 127.0.0.1:27017 - 
Local(undefined:undefined)]
name: 'MongoError',
message: 'connect UNKNOWN  == null
at C:\node-mongodb\simple-server.js:8:12
at C:\node-mongodb\node_modules\mongodb\lib\mongo_client.js:330:20
at C:\node-mongodb\node_modules\mongodb\lib\db.js:231:14
at null.<anonymous> (C:\node-mongodb\node_modules\mongodb\lib\server.js:240:9)
at g (events.js:260:16)
at emitTwo (events.js:87:13)
at emit (events.js:172:7)
at null.<anonymous(C:\nodemongodb\node_modules\mongodb\node_modules\mongo
db-core\lib\topologies\server.js:218:12)
at g (events.js:260:16)
at emitTwo (events.js:87:13)