since you can achieve it for a month, you might as well write a script that can change the sql statement according to the passed parameters and change the corresponding time. Every time the boss asks you to guide, you execute the file, and then pass in the time your boss gives you. Will it be more convenient, a rookie, and do not scold if there is no good way!

it is recommended that the master write the stored procedure. You can write a for loop to concatenate the strings of the table name.

who makes your boss unhappy? ha ha
has been divided into daily tables, so it can only be union.
if you want to make it easier, transform these tables into partitioned tables, one partition a day according to the time field in the table. In this way, the management is not much different from the daily watch, when you need to check the data, you only need to use the time field to limit the scope, one month, one year, half a year, whatever you want. Build an index on the time field, and you can run more comfortably.

this is heterogeneous storage.
you can listen to musql binlog, to write all the data to a table and then read it from that table. The implementation can use Alibaba's open source canal.