1, need to query the data in a table for a certain month.
2, for example, to query all activities in September in the activity table. Any year is fine. Only activities that fall in September will be selected.
3, using springdatamongo. how to assemble this condition with criteria.
4, aggregate function temporarily don’t want to use, because want to use paging, aggregate a count is not worth it
Use the time of data processing by the time function to obtain the month as the condition:
`where date_func(time) = 9`