Catch exeption from database insert

Developing a web application, I'm using insert () to add registers to the database.  I'm using the optional parameter to return a boolean value so I can check if it succeeded.

The problem is that if I try to insert a new register with a yet existing key CodeIgniter catch the exception and shows the tracing information.  So I added a try..catch but it doesn't catch anything.

The code I use is:

PHP Code:

try
{
  $Result = $this->insert ($Data, false);
}
catch (\Exception $Error)
{
  log_message ('error', $Error->getMessage ());
  $Result = false;
} 


I've tried several exception classes (including CodeIgniter\Database\Exception\DatabaseException) but nothing works, neither debug mode nor production mode: CI overrides my code.  finally does work though.

Why is CI overriding my try..catch blocks and how can I prevent it?

P.S: I've search both in forums and in the Internet but I've found only old threads (CI3 or CI2) or unrelated with my problem.

P.S.2: If you'll say that I should check data before insert (as I've read in some old threads), I shouldn't:  I want the database to check data integrity and just check if it succeeded.  That's why relational databases were invented for, aren't they?