Re: constraint modification

Sorry,

You can only use alter table modify with null/not null. For other constraints like fk, you'll have to drop them and recreate them. I think there will be no problem with that. To the best of my knowledge, oracle does not have an on delete set null option, only on delete cascade.

Regards,

Andre

Doug Cowles escreveu na mensagem <385A706F.6ADF7ED2_at_nospambigfoot.com>...
>Is there any way to take an existing foreign key constraint and modify
>it to also
>be on delete cascade or on delete set null without recreating the
>constraint from scratch?
>
>For example -
>create table A( a number);
>alter table A add constraint apk primary key (a);
>create table B( b number);
>alter table B add constraint bfk foreign key (b) references A(a);
>
>SQL>alter table B modify constraint bfk on delete cascasde;
>alter table B modify constraint bfk on delete cascasde
> *
>- > SQL comand not properly ended
>
>alter table B modify b add constraint bzy foreign key(b) references A(a)
>on delete
>cascade;
>-> Such a constraint already exists in the table..
>
>alter table B modify b on delete cascade
>-> invalid datatype
>
>etc.,
>
>any way to do this?
>
>- Dc.
>
Received on Sun Dec 19 1999 - 09:07:53 CST