Re: Adding "on delete cascade" after table creation ?

On Thu, 19 Sep 2002, Peter Alberer wrote:

> Hi there,
>
> i have a table that SHOULD look like this:
>
> create table lr_object_usage (
>     lr_object_usage_id      integer
>                             constraint
> lr_object_usage_lr_object_usage_id_pk
>                             primary key,
>     lr_object_id            integer
>                             constraint lr_object_usage_lr_object_id_fk
>                             references lr_objects(lr_object_id)
>                             on delete cascade,
>     access_time             timestamp,
>     user_id                 integer
>                             constraint lr_object_usage_user_id_fk
>                             references users(user_id),
>     status                  varchar(11),
>     context                 integer
>                             constraint lr_object_usage_context_fk
>                             references
> lr_object_usage(lr_object_usage_id)
>                             ___ON DELETE CASCADE___
> );
>
> unfortunately i think that the table was created without the delete
> cascade in the last line (for the constraint
> lr_object_usage_context_fk). Is it somehow possible to add the delete
> cascade without recreating the table?

You'll probably have to manually remove the triggers for the foreign
key constraint (see techdocs.postgresql.org's fk primers for info) and
then use alter table add constraint.