quote:

---

Originally posted by nigelrivett

yes

create trigger tr_tbl on tbl for update
as

if update (mycolumn)
begin
if exists
(
select * from inserted i
join updated u
on i.pk = u.pk
and (i.mycolumn <> u.mycolumn or (i.mycolumn is null and u.mycolumn is not null) or (i.mycolumn is not null and u.mycolumn is null))
)
begin
rollback tran
raiserror ('cannot update column', 16, -1)
end
end

==========================================
Cursors are useful if you don't know sql.
SSIS can be used in a similar way.
Beer is not cold and it isn't fizzy.

---

nigelrivett,
As I aware of the logical tables of trigger there 
are only two tables inserted and deleted.Updated 
table is not the logical one .Correct me If I am 
wrong ..