Re: Request for Implementation of Custom Error Messages for CHECK Constraints - Mailing list pgsql-hackers

On Sat, May 10, 2025 at 07:58:47PM -0400, Tom Lane wrote:
> "Miguel Ferreira" <miguelmbferreira@gmail.com> writes:
> > I propose extending the syntax of the ALTER TABLE ADD CONSTRAINT
> > statement (and potentially CREATE TABLE) to allow for the
> > specification of a custom error message for each CHECK constraint.
> 
> Why don't you just choose better names for your constraints?
> 
> I'd argue that the proposed change might actually be a net loss
> for usability, if it entirely obscures the fact that what happened
> was a check-constraint violation.
> 
> It's also not very clear why we'd stop with check constraints,
> if the desire is to get rid of database-produced error messages
> in favor of something that somebody likes better.

Yeah, you could name the constraint
"Custom_error_message_when_the_condition_is_not_met." and then just
convert underscore to spaces and display that to the user.

-- 
  Bruce Momjian  <bruce@momjian.us>        https://momjian.us
  EDB                                      https://enterprisedb.com

  Do not let urgent matters crowd out time for investment in the future.