Re: Dual - multiple rows

Can we add trigger on dual to make sure that it can only have one record?

Thomas Kyte <tkyte_at_us.oracle.com> wrote:

> A copy of this was sent to g.renfrew_at_acca.org.uk
> (if that email address didn't require changing)
> On Thu, 02 Sep 1999 10:11:43 GMT, you wrote:

>>Hi everyone,
>>
>>I'm running 7.3.2.3 on Solaris 2.6 and came across a bit of a weird
>>problem with the DUAL table. When I selected from DUAL it always
>>returned two identical rows. On all my other databases I would only
>>ever expect one row returned, as is normal. This problem caused a
>>couple of errors with "ora-1422: exact fetch returns more than
>>requested number of rows". When I did "select * from dual" it returned
>>the following:
>>DUMMY
>>-----
>>X
>>x
>>
>>Since all my other databases returned only 'X' I deleted from dual
>>where DUMMY = 'x' and everything is ok now.
>>Any ideas on how an extra row would appear in DUAL?
>>

> somebody inserted it (one of your DBAs probably).

> DUAL is a real table -- its not special or anything. If it has no rows -- > that'll cause havoc. If it has >1 row, same thing.

>>Best Regards
>>Graeme Renfrew
>>DBA
>>ACCA
>>Glasgow
>>
>>
>>Sent via Deja.com http://www.deja.com/
>>Share what you know. Learn what you don't.

> -- 
> See http://govt.us.oracle.com/~tkyte/ for my columns 'Digging-in to Oracle8i'...
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>  
> Thomas Kyte                   tkyte_at_us.oracle.com
> Oracle Service Industries     Reston, VA   USA

> Opinions are mine and do not necessarily reflect those of Oracle Corporation

--
Have several nice days... Received on Fri Sep 03 1999 - 04:49:53 CDT