Everything works fine when I used shell v3.6. After updating to v4.2.3 I got this error. Tried several commands from stackoverflow but no luck. I am using linux mint 19.3 (based on Ubuntu 18.04)
MongoDB shell version v4.2.3
connecting to: mongodb://127.0.0.1:27017/?compressors=disabled&gssapiServiceName=mongodb
2020-03-05T00:30:14.956+0600 E QUERY [js] Error: couldn’t connect to server 127.0.0.1:27017, connection attempt failed: SocketException: Error connecting to 127.0.0.1:27017 :: caused by :: Connection refused :
connect@src/mongo/shell/mongo.js:341:17
@(connect):2:6
2020-03-05T00:30:14.958+0600 F - [main] exception: connect failed
2020-03-05T00:30:14.958+0600 E - [main] exiting with code 1
