要连接mongo，我们必须首先启动“mongod”服务。 您可以看到以下输出:

$ mongod
2017-03-05T00:31:39.055+0530 I CONTROL  [initandlisten] MongoDB starting : pid=1481 port=27017 dbpath=/data/db 64-bit host=Prabhu-Nandans-Mac.local
2017-03-05T00:31:39.056+0530 I CONTROL  [initandlisten] db version v3.4.2
2017-03-05T00:31:39.056+0530 I CONTROL  [initandlisten] git version: 3f76e40c105fc223b3e5aac3e20dcd026b83b38b
2017-03-05T00:31:39.056+0530 I CONTROL  [initandlisten] OpenSSL version: OpenSSL 1.0.2k  26 Jan 2017
2017-03-05T00:31:39.056+0530 I CONTROL  [initandlisten] allocator: system
2017-03-05T00:31:39.056+0530 I CONTROL  [initandlisten] modules: none
2017-03-05T00:31:39.056+0530 I CONTROL  [initandlisten] build environment:
2017-03-05T00:31:39.056+0530 I CONTROL  [initandlisten]     distarch: x86_64
2017-03-05T00:31:39.056+0530 I CONTROL  [initandlisten]     target_arch: x86_64
2017-03-05T00:31:39.056+0530 I CONTROL  [initandlisten] options: {}
2017-03-05T00:31:39.056+0530 W -        [initandlisten] Detected unclean shutdown - /data/db/mongod.lock is not empty.
2017-03-05T00:31:39.057+0530 I -        [initandlisten] Detected data files in /data/db created by the 'wiredTiger' storage engine, so setting the active storage engine to 'wiredTiger'.
2017-03-05T00:31:39.057+0530 W STORAGE  [initandlisten] Recovering data from the last clean checkpoint.
2017-03-05T00:31:39.057+0530 I STORAGE  [initandlisten] wiredtiger_open config: create,cache_size=3584M,session_max=20000,eviction=(threads_max=4),config_base=false,statistics=(fast),log=(enabled=true,archive=true,path=journal,compressor=snappy),file_manager=(close_idle_time=100000),checkpoint=(wait=60,log_size=2GB),statistics_log=(wait=0),
2017-03-05T00:31:39.620+0530 I CONTROL  [initandlisten] 
2017-03-05T00:31:39.620+0530 I CONTROL  [initandlisten] ** WARNING: Access control is not enabled for the database.
2017-03-05T00:31:39.620+0530 I CONTROL  [initandlisten] **          Read and write access to data and configuration is unrestricted.
2017-03-05T00:31:39.620+0530 I CONTROL  [initandlisten] 
2017-03-05T00:31:39.620+0530 I CONTROL  [initandlisten] 
2017-03-05T00:31:39.620+0530 I CONTROL  [initandlisten] ** WARNING: soft rlimits too low. Number of files is 256, should be at least 1000
2017-03-05T00:31:39.643+0530 I FTDC     [initandlisten] Initializing full-time diagnostic data capture with directory '/data/db/diagnostic.data'
2017-03-05T00:31:39.643+0530 I NETWORK  [thread1] waiting for connections on port 27017
2017-03-05T00:31:40.008+0530 I FTDC     [ftdc] Unclean full-time diagnostic data capture shutdown detected, found interim file, some metrics may have been lost. OK
2017-03-05T00:32:03.832+0530 I NETWORK  [thread1] connection accepted from 127.0.0.1:49806 #1 (1 connection now open)
2017-03-05T00:32:03.833+0530 I NETWORK  [conn1] received client metadata from 127.0.0.1:49806 conn1: { application: { name: "MongoDB Shell" }, driver: { name: "MongoDB Internal Client", version: "3.4.2" }, os: { type: "Darwin", name: "Mac OS X", architecture: "x86_64", version: "16.4.0" } }
2017-03-05T00:32:08.376+0530 I -        [conn1] end connection 127.0.0.1:49806 (1 connection now open)

然后打开另一个终端，输入“mongo”。

输出如下:

$ mongo
MongoDB shell version v3.4.2
connecting to: mongodb://127.0.0.1:27017
MongoDB server version: 3.4.2

你的问题解决了:)

是操作系统

检查服务状态:

brew services

如果你有这样的东西:

Name              Status
mongodb-community error

所以你可以像这样停止并重新启动服务:

brew services stop mongodb-community
brew services start mongodb-community

今天就发生在我身上，我用下面的方法解决了它。

机器:我使用的是Windows 10机器，下载了最新的MongoDB - Community版。

所以，问题是，我没有创建C:\data\db。

在没有创建C:\data\db的情况下，我打开CMD终端，在终端上使用mongod命令启动数据库

C: \ YourInstallationPath \ bin > mongod

当我发射mongo命令时，我遇到了问题。

Twist，我创建了必要的文件夹，但仍然遇到了问题。这是因为mongo服务器已经在运行。为了解决这个问题，我再次启动mongod命令，它会自动引用C:\data\db。

其他用户建议添加C:\data\db，但没有再谈到执行mongod，这正好解决了我的问题。

我在ubuntu上得到这个错误，但你可以尝试以下命令:

sudo service mongod start

首先，你必须启动mongod服务器，然后在另一个终端，你必须启动mongo shell。

启动，mongo服务器

1. 如果你的路径是默认路径(data/db) 简单的解雇了蒙神在终端

2. 如果您的路径不是data/db，那么您可以像这样命令 遵循: Mongod—dbpath“你的路来了”。

对于开始mongo shell， 只是在另一个终端解雇了蒙戈

如果你在端口27017上等待连接，那么你的mongo成功启动了。

希望你能明白我的意思

这工作我:-

以Mongodb 3.2为窗口，启动Mongodb服务。因此，以管理员身份运行命令提示符，然后net start MongoDB