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Re: How to drop a foreign key

From: Michel Cadot <micadot_at_netcourrier.com>
Date: Wed, 11 Apr 2001 09:33:33 +0200
Message-ID: <9b11ce$m0u$1@s1.read.news.oleane.net>

"David YEUNG" <dyeung_at_ust.hk> a ecrit dans le message news: 3AD3D84A.27B789E1_at_ust.hk...
> I have a table A which contains a foreign key reference to
> table B's primary key, e.g.:
>
> create table A (
> ...
> fid varchar2(16) not null,
> ...
> foreign key (fid) references B(pid) on delete cascade
> )
>
> where pid is the primary key of the table B.
>
> Can someone tell me how to drop (or disable) the foreign key in table A.
>
> Thanks
>
> david

First, it is a goog thing to always name your constraint:  create table A (
   ...
   fid varchar2(16) not null,
   ...
   constraint A_fk foreign key (fid) references B(pid) on delete cascade  )
it is easier to drop them with alter table: alter table A drop constraint A_fk;

Now, you have to find the name generated by the system for your constraint:
select constraint_name, r_constraint_name from user_constraints
where table_name='A' and constraint_type='R'; r_constraint_name is the unique/primary key constraint on your B table. constraint_name is the actual name of your constraint. Then you can drop the constraint with alter table.

--
Have a nice day
Michel
Received on Wed Apr 11 2001 - 02:33:33 CDT

Original text of this message

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