Обсуждение: Query

hello

2008/6/24 kartik <kartik@v2technocrats.com>:
> Hello there
>
> Can anyone please tell me how to make a column uneditable….
>
> Plz  give me some output
>
> thans

try trigger

create table foo(
  a varchar
);

create function a_update_trg()
returns trigger as $$
begin
  if new.a is distinct from old.a then
    raise exception 'cannot change column a';
  end;
  return new;
end;
$$ language plpgsql;

create trigger foo_trg_update after update on foo for each row execute
procedure a_update_trg();

regards
Pavel Stehule

am  Tue, dem 24.06.2008, um 15:19:46 +0530 mailte kartik folgendes:
> Hello there
>
> Can anyone please tell me how to make a column uneditable?.

You can write a TRIGGER to avoid changes on the column. Within the
TRIGGER you can compare OLD.column with NEW.column and there you can
raise an error if there are differences.


Andreas
--
Andreas Kretschmer
Kontakt:  Heynitz: 035242/47150,   D1: 0160/7141639 (mehr: -> Header)
GnuPG-ID:   0x3FFF606C, privat 0x7F4584DA   http://wwwkeys.de.pgp.net

Perhaps trivial, but:
Additional to or instead of triggers You can use grants to allow updates only to special users.

Ludwig

>Hello there
>
>Can anyone please tell me how to make a column uneditable..
>
>Plz  give me some output
>
>thans
>