Re: create assertion?

From: eugene kim <eugene1977_at_hotmail.com>
Date: Mon, 09 Sep 2002 04:02:12 +0000
Message-ID: <algd3t$dtl$1@newsreader.mailgate.org>

is there an equivalent of 'create assertion' in oracle? or do i have to get around with triggers?

desired assertion is like this

---

no team may play two games in two different places on the same day..

---

this is how i'm trying..

create or replace trigger assertion_on_game

        before insert or update on games for each row
begin

        if exists ( select home_team_id 
                from teams t
                where t.home_team_id = :new.visitor_team_id or -- inserted
 visitor team has game in home city
                t.visitor_team_id = :new.home_team_id and -- inserted home 
team has game in visitor city
                game_date = :new.game_date) then
        <don't update or insert>
        end if;
end;
/       

thank you Received on Sun Sep 08 2002 - 23:02:12 CDT