How Many Queries can hit on a single database in a day

If I may please answer your question by a question.

 

Is there a reason why such a question has come to your mind. Are you facing a issue? Do you believe you already have reached such a limit? Is your manager asking? Are you asking because you are provisioning something? Or do you want to limit things deliberately?

 

These questions are important.

 

Otherwise, there is no limit. The only limit is the hardware and network, I think. I know of no other such limit.