Answer 1

I hope you realize that HTML is a client-side technology which means the user is free to view/edit the content once it was downloaded into the browser.

That means secrets like password for DB access will be exposed to anyone regardless of whether encryption is in place.

[ Short answer ]
Yes it's possible, just Google with keyword "javascript db"

[ Long answer ]
As mentioned before this, DB access is always done with server-side technology (i.e. C#, Java, Python, PHP & etc.) for web application as the implementation is hidden from the public.