Re: abnormal behaviour of a CHECK CONSTRAINT with a regular expression when a trigger is added

Daniel Struck <struck.d@retrovirology.lu> writes:
> This makes it also impossible to change the type of a value by a trigger?

Correct.  It is annoying in some cases, but if the input to the trigger
isn't of the column datatype, then what type is it?  It's hard to see
how that could work in general.

If you want, say, a varchar length constraint to be checked only after
the trigger runs, I'd counsel declaring the column as plain text and
writing the length test as a CHECK constraint.

            regards, tom lane