Calculate retention with SQL

1

Having a table containing UserID and dates only:

ID | Date

111 | 01/01/2021
222 | 30/01/2021
333 | 22/01/2021

Desired output would be (active users are users that have an activity in the past 30 days, retained users are users who were active before that ):

Date | Number_of_Active_users | Number_of_Retained_users | Retention%

01/01/2021 | 3 | 2 | 22%
03/01/2021 | 8 | 4 | 60%

Thanks

2

welcome!

definitely some missing data. what you have does not seem to be the whole truth

3

Thanks!
It is one table that retention should be extracted from.
There are no other tables.

4

What is a retained user? How is the retention percent calculated? What have you tried?