当我尝试从腻子运行mongo命令时，它给了我以下错误，有人可以帮助我，如何解决此错误？
MongoDB shell version v3.6.3
connecting to: mongodb://127.0.0.1:27017
2019-01-17T04:29:27.984-0500 W NETWORK [thread1] Failed to connect to 127.0.0.1 :27017, in(checking socket for error after poll), reason: Connection refused
2019-01-17T04:29:27.984-0500 E QUERY [thread1] Error: couldn't connect to ser ver 127.0.0.1:27017, connection attempt failed :
connect@src/mongo/shell/mongo.js:251:13
@(connect):1:6
exception: connect failed