problem description
constant: number of active people, number of registrants, recharge amount, etc.
proportion: proportion of paid people, proportion of lost users, etc.
increase or decrease: the number of registered people rises year on year, the number of lost users decreases compared with last month
the environmental background of the problems and what methods you have tried
at present, constant data can be obtained or "timed time interval" data can be obtained according to the find () syntax in mongodb
but how to batch cycle the annual, quarterly and monthly data for calculation?
if there is source code in the previous question, it is no longer copy and paste. This question is just looking for ideas and methods