Databases: Making a Log of actions, how to handle various references?

Question

hope you all had a happy new year.

So, my question is, what\'s the best way to make a log of actions. Let me explain it with a example, suppose we have these entities:

Answer 1

My answer to Whats a better strategy for storing log data in a database?:

It depends on the purpose of logging. For debugging and general monitoring purpose, a single log table with dynamic log level would be helpful so you can chronologically look at what the system is going through.

On the other hand, for audit trail purpose, there's nothing like having duplicate table for all tables with every CRUD action. This way, every information captured in the payment table or whatever would be captured in your audit table.

So, the answer is both.

Edit: To implement it cleanly with referential integrity and have all the flexibility, I suggest having duplicate audit trail table for all CRUDs for each table even if it's "heavy." The business rules are more volatile compared to data structures anyway, so by keeping log logic in code/query you retain the flexibility. For example, suppose you decided not to track when the users left a group. Later day, the clients asked that it's very important to track the information. All you have to do now is change the query so deletion of user_group record is part of the result.