Is there way to give user-friendly error message on constraint violation

Question

Say I have column Gender and constraint CHECK( Gender IN (\'F\', \'M\', \'OTHER\')).
If I accidentally forgot to handle this on client side, us

Answer 1

If you are looking for a way to tell Oracle always to replace the exception message "ORA-02290: check constraint (SYS_C099871244) violated" by another message like "ORA-20001: Gender must be F or M", then the answer is: no, it can't be done.

What you can do is provide a solution that can be used by developers in their code something like this:

...
begin
    insert into emp (empno, gender) values (p_empno, p_gender);
exception
    when others then
       error_pkg.handle_exception;
end;

The error_pkg.handle_exception procedure would parse the Oracle exception message and extract the name of the constraint (if it was a constraint violation) and lookup that constraint name in a cross reference table to get the required message, then use raise_application_error to re-raise the exception with the new message.

I suppose Oracle could offer a package and table like this as standard, but perhaps since in practice there are many different requirements for error handling in system, it isn't considered to be generally useful enough.