Re: Nested tables - what are the uses?

Hello!

I also wanted to know a bit more about nested tables. Does it make sense to convert existing foreign key relationships on regular tables into nested?

Also, how can one specify that nested table is to have columns that are reqired? (NOT NULL does not work for type definitions). Also, if nested table has columns that are foreign keys into other tables, how can this be defined?

And, finally, how can I select something from the nested table, where there is more than one record in the main table? The examples I look at always do selects, where the record set from the main table is limited. If I do plain select without, the WHERE I get the ORA-01427: single-row subquery returns more than one row...

Any comments on the nested tables -- pros and cons would be GREATLY appreciated.

Sincerely,

Alex Vilner

In article <850bvl$g76$1_at_nnrp1.deja.com>,   argosy22_at_my-deja.com wrote:
> Hi all,
>
> I've just been reading about these nested
> tables. A table within a table.
>
> My first reaction is that while this allows
> you to lots of things with objects, it seems
> to be violating standard database design.
>
> In Oracle 8, you could have a table of
> student, with a nested table of COURSES
> inside it.
>
> In Oracle 7, you would instead have
> a 1:Many, or Many:Many table to show this
> information. Is this part of a new SQL standard?
>
> What have you people been using Nested tables
> for? What has your experience been like?
>
> Ciao,
>
> Argosy
>
> Sent via Deja.com http://www.deja.com/
> Before you buy.
>

Sent via Deja.com http://www.deja.com/
Before you buy. Received on Mon Jan 17 2000 - 15:57:44 CST