Обсуждение: No reference to inherited columns?

Поиск
Список
Период
Сортировка

No reference to inherited columns?

От
"Christian Marschalek"
Дата:
Can it be that I cannot reference to any inherited columns? Or is there
a special way to do it? The manual doesn't seem to cover this one...

Thx Chris


Re: No reference to inherited columns?

От
Stephan Szabo
Дата:
On Wed, 9 May 2001, Christian Marschalek wrote:

> Can it be that I cannot reference to any inherited columns? Or is there
> a special way to do it? The manual doesn't seem to cover this one...

Well, if you mean reference a subtable's copy of an inherited column,
you should be able to do this as long as you create a unique index
on the subtable's copy of the inherited column (create unique index
subtable_column on subtable(column)) before you try to define the
constraint.
Example:
create table base (id int);
create table child (subvalue int) inherits (base);
create unique index child_id on child(id);
create table fk (childid int references child(id));

If you want to reference an entire tree (ie, reference a parent's
copy of a column and have it also reference children) you're
currently not able to do that.