Markus -
It is a very common design pattern to do the following:
* Put your entities in a data espace.
* Set them to "Public" = "Yes" and "Expose Read Only" = "Yes"
* Create Actions to provide insert/update and delete functionality that works the way you want it to, make those public. For example, a "delete" Action might not actually run "delete" it could set "IsActive" = "False" and save it. These actions usually do things like set an updated (or created) on timestamp and user ID, validate any business logic or data integrity issues before trying to save or delete, provide friendly "plain English" error messages instead of letting the SQL fail and give an ugly error message, etc.
This is NOT an OutSystems-specific pattern, it is a general programming "best practice" pattern, and I highly recommend it. The downside is that you cannot easily drag/drop screens together, but if you set it to be "read only" = "no", you can drag/drop screens properly again, then flip it back and change the uses of the built-in CRUD commands with your new actions.
It is a much better way of doing things.
J.Ja