Re: VARCHAR2: NULL value vs. empty string

Hello Daniel,

The stuff is below:

"Daniel Morgan" <damorgan_at_x.washington.edu> wrote in message news:1071424787.771334_at_yasure...
> VC wrote:
> > Secondly, I see you've conveniently skipped Oracle's own admission of
> > non-compliance:
> > "In the SQL 92 standard, a character string of length zero is distinct
from
> > a
> > null string.
> > " (
> >

http://www.engin.umich.edu/caen/wls/software/oracle/appdev.901/a88879/adl07m
> > 13.htm#126418 )
>

[DM]
> Last time I checked www.engin.umich.edu was not an Oracle web site. And
> the last time I checked was two minutes ago.

OK., here's the same information from the horse's mouth: http://download-west.oracle.com/docs/cd/B10501_01/appdev.920/a96591/adl07mds .htm#126418

<quote>
Note::
IS NULL Semantic Discrepancy

In the SQL 92 standard, a character string of length zero is distinct from a null string.

For an initialized LOB of length 0, you should expect `IS NULL' to return zero (FALSE), since it is the correct and standard compliant behavior. In contrast, a VARCHAR2 of length 0 returns TRUE on 'IS NULL`. </quote>

I must admit I'm quite disappointed by your obvious failure to conduct a logical discussion and inability to admit that you'd been mistaken on the subject of such trivial nature. Apparently, I was misled by your other, more reasonable, postings.

This is my last message in the thread as anyone with a kindergarten level logic grasp can easily read and understand the SQL'92 standard snippet I posted earlier. Oracle's own admissin of non-compliance is really redundant for the discussion. For Oracle fans, it may be interesting to know that the very VARCHAR2 data type is non-standard -- SQL'92 does not define it.

Rgds.

VC Received on Sun Dec 14 2003 - 17:35:15 CST