connection failed?

Hi, I am getting the below error every time. Please help.
```
[nodemon] 2.0.2
[nodemon] to restart at any time, enter `rs`
[nodemon] watching dir(s): *.*
[nodemon] watching extensions: js,mjs,json
[nodemon] starting `node ./backend/server.js`
connection failed
```

and can I deploy local database?