Re: SELECT within the FROM clause?

"Jaap W. van Dijk" <j.w.vandijk.removethis_at_hetnet.nl> wrote in message news:45032690.363890_at_news.hetnet.nl...
> On Sat, 09 Sep 2006 20:22:51 GMT, "Dereck L. Dietz"
> <dietzdl_at_ameritech.net> wrote:
>
> >
> It's called an inline view, and it serves the same purpose as a normal
> view, but now coded inside the complete statement itself. It's been
> around since Oracle 8 if my memory serves me right.
>
> From Oracle 9 on, you can even put a SELECT in the SELECT list, like
>
> SELECT (SELECT 1 from dual) from dual;
>
> This is called a scalar select. It is allowed to yield only one
> value, so
>
> select (select 1,2 from dual) from dual;
>
> is illegal, as is
>
> select (select 1 from dual union select 2 from dual) from dual;
>
> Jaap.

Okay thanks. Would you happen to know of the top of your head if it is as efficient as creating an actual view to put in the query or are they about the same? Received on Sat Sep 09 2006 - 16:52:39 CDT