> On Wed, Jan 08, 2003 at 01:13:03PM -0500, Ron Peterson wrote:
>> On Tue, Jan 07, 2003 at 11:01:08AM -0500, Tom Lane wrote:
>>
>> > > I thought that the idea behind noup was to protect single columns
>> from
>> > > update. However, when I apply the noup trigger as above, I can't
>> > > update /any/ column. Is this the intended behaviour?
>> >
>> I'm going to see if I can create this function.
>
> Well, I think I've thunk something up. Of course I'm happy to submit
> my modification for distribution or ridicule, as the case may be.
> Where should I submit this?
>
> I made a function noupcols() which takes one or more column names as
> arguments. The function then creates a new tuple by getting the old
> values for those columns, and then doing an SPI_modifytuple on the new
> tuple using the old values for those columns.
>
> I'm kind of flying by the seat of my pants here, so if anyone would
> care to critically review my code, by all means...
Sounds similar to the plpgsql example at:
http://www.archonet.com/pgdocs/lock-field.html
which silently discards changes. It's trivial (apart from quoting issues)
to write a trigger generator to customise the above in plpgsql (see the
Cookbook on techdocs.postgresql.org for examples)
- Richard Huxton