Connecting custom actions to a MonogoDB database

I am pretty new to working with databases. I have figured out how the basics of rasa NLU and core work along with intents and entity extraction. My next step is to connect my bot to a database where I can fetch details about a user based on the name of the user through a database, can anybody help me setup a basic example as to hoe I do that through custom actions?

Hi, did you find any examples? I am looking for one too. Thanks.