So this is the basic problem with web apps. If you have a huge user base ( more then say 500 ), then provisioning them in the database, while this is very easily doable, it is something most web programmers, sadly, don't want to deal with and want only ONE connection user for the database. You have already shot yourself in the foot because you don't have the created_by,modified_by, created_date, modified_date in the tables. To fix this you really only have one choice:
- Put the columns on the tables and force the UI people to push the "network" user name through. The rest of the columns can be handled by one very simple trigger.
Why DB audit will not help you:
The DB audit feature ONLY deals with users defined as actual users in the database, sorry that is just the way it is.
Here are some things to look at when dealing with a front end system.
You can write SP's or Packages that execute as the schema owner, but can be run by ANYONE who is defined in the database and those can handle all the INSERT, UPDATE, DELETE operations on the schema they are defined in by simply giving other users the EXECUTE privilege on that set of SP's. This give the DB fine grain control over how tables are manipulated and you only have to grans the select privilege to all the users.
You can write a SP or Package in the SYSTEM schema that allows a group of people to provision users on the system by granting the execute privilege on that SP. Within that SP you define what ROLES they are assigned and therefor can control all their access.