How to upgrade Mongodb 4.0 to 4.2 without senrenren

I needed to update my MongdoDB from 4.0 to 4.2 I was not sure how to go about it and thought I lost my data at a point and was soo sad. So I am writing this so you don’t have to be sad, friend ( ͡ᵔ ͜ʖ ͡ᵔ ).

Download the new Mongo version from their website. I use windows so I got the msi installer. Don’t install it yet if you want.
Create a backup of your current database: Open cmd and go to where your current Mongo is then run mongodump. This will create a backup of all your databases into a folder called ‘dump’. Make a copy of that folder somewhere else…
Uninstall your current MongoDB; delete the ‘4.0’ folder. No fear you have a backup
Now install that new MongoDB version you got. And make sure to update your system path variables if necessary
Restore the backup you created earlier: Run mongorestore in the bin folder of your new installation. Open mongo shell and run show dbs to confirm the databases are back
Start the Mongo service if it’s not running already

That’s it. No senrenren

sources:

Stackoverflow question

Create backups with mongodump and mongorestore