Re: NULL string handling

From: Ari Kaartinen <Ari.Kaartinen>
Date: 1995/04/24
Message-ID: <3nffm0$frl_at_idefix.eunet.fi>#1/1

gladish_at_elvis.suite.com (Brian Gladish) wrote:

>I'm quite surprised at Oracle's handling of NULL strings ...
>
>I believe that NULL || <anything> should be NULL, and that '' (the empty
>string) should not return TRUE for IS NULL. Is there an option
>EMPTY_STRING_IS_NOT_NULL or an IS REALLY NULL operator? Am I missing
>something?

 This is a bug that Oracle calls a feature. Currently zero-length string is (almost always) treated as NULL. This is going to be fixed 'in a future release'. A quote from $ORACLE_HOME/rdbms/doc/README.doc (version 7.1.3.2.1):

  3.3 Planning for Future Releases

---

     Beyond Oracle7 Server release 7.1, future releases will have changes for   which you can prepare now. If you follow these recommendations, migration   to newer releases of Oracle will be easier.

  Feature                             Recommendation
  ---------------------------------   ----------------------------------------
  A string of zero length ('')        Your application should use a NULL when
  is not equivalent to a NULL         the value is unknown.

--
Ari Kaartinen             Tekla Oy, Koronakatu 1, SF-02210 Espoo Finland

Ari.Kaartinen_at_tekla.fi Tel: +358-0-8879511 Fax: +358-0-8039489 Received on Mon Apr 24 1995 - 00:00:00 CEST