Louis-David Mitterrand <cunctator(at)apartia(dot)ch> writes:
> Is there a way (outside of RULEs and TRIGGERs) to make a field
> read-only once it is INSERTed or assigned its default value? I'm
> thinking, for example, of the "created" column that I add to most
> tables, holding the row's creation timestamp.
An on-update trigger seems like a very simple solution here.
You could either copy the old value into the new, or raise an
error if they are different, depending on what you want.
regards, tom lane