Re: REPOST: Outer join and the OR operator

It is not clear what problem you have from the posting.

Usually in outer join, columns in both sides of comparison operator in where clause from different tables. In your query, one side are constants. So why do you need a outer joint here.

In article <7j6m9k$oco$1_at_nnrp1.deja.com>,   mrkonjic_me_at_my-deja.com wrote:
>
>
> Hi,
>
> I am working on a temporal database which uses an
> 'Effective Date' and 'Ending Date' attribute for each
> major entity. An Active (as opposed to an Historic
> or Future) record is defined as follows:
>
> 1. Effective date <= SYSDATE
> 2. (Ending Date IS NULL OR Ending Date > SYSDATE)
>
> When I try to outer join two tables incorporating
> the above constaints, Oracle won't allow me to use
> an OR in the outer join syntax.
>
> I've read the manuals and understand that this is
> as to be expected. My question is, does anyone
> have a work around?
>
> Also, I suspect that it was not a good idea to
> define an Active record as one with either a NULL
> Ending Date OR an Ending Date > SYSDATE, ie two
> definitions for the same thing. What is the common
> practice for specifying an Active record which has
> a NULL Ending Date?
>
> Is it better to replace the use of NULL with a constant
> date value that is far into the future, such as the
> Year 3000 or the maximum date supported by Oracle?
>
> Thank-you, Brian Mrkonjic
>
> Sent via Deja.com http://www.deja.com/
> Share what you know. Learn what you don't.
>

Sent via Deja.com http://www.deja.com/
Share what you know. Learn what you don't. Received on Thu Jun 03 1999 - 18:57:08 CDT