Apex pre-validation of database relational constraints

Question

I have created an apex form to maintain a code table with insert, update, and delete. The code table is pointed to by a number of foreign keys. As the application grows, other teams may reference this code table with even more foreign keys long after the page has been written.
Whenever I delete a record that is referenced by a foreign key, I get an error from the database as you would expect.
The error displays to the good old trusty single error page and mentions table names, oracle error codes, constraint names and all the stuff that us programmers like to see.
I do not want the user to see any of this.
How can I test for a constraint violation, gracefully format the error, and display it back to the user?
I would like to create a page level validation that tests for a database level constraint violation without sending the user to the single error page. Is this possible without checking every single dependent table manually?
Thank you,
Jerry.

Answer 1

I would like to create a page level validation that tests for a database level constraint violation
Well, you could create a page level validation of type "PL/SQL function body returning error text" where you would duplicate the DML action (update or delete) that is going to take place on the record, trap the error as usual in a WHEN OTHERS exception block and return a user-friendly error message. Since the validation fails, the real DML process will not execute and so users won't see the "ugly" error message.