runmongodCommand, mongoDB can be started

This should be regarded as a success, right?

But runmongoIf so, the terminal will report such an error:

MongoDB shell version: 3.2.7
 connecting to: test
 2017-01-31T12:56:00.745+0800 W NETWORK  [thread1] Failed to connect to 127.0.0.1:27017, reason: errno:61 Connection refused
 2017-01-31T12:56:00.745+0800 E QUERY    [thread1] Error: couldn't connect to server 127.0.0.1:27017, connection attempt failed :
 connect@src/mongo/shell/mongo.js:229:14
 @(connect):1:6
 
 exception: connect failed

I don’t know why ~ ask for advice, thank you!