Re: [Q] Porting SQL to Oracle

Tony wrote:

> Billy Verreynne <vslabs_at_onwe.co.za> wrote in message news:<bcbtjt$d57$1_at_ctb-nnrp2.saix.net>...
> > Treating NULL as a state (which it is from an OO perpective), Oracle's way
> > of dealing with NULL is not strange at all. It works exactly the same way
> > in the OO code I write.
>
> I don't have a copy of the SQL:1999 standard to refer to, but Oracle's
> own documentation states that Oracle doesn't conform to the standard
> on '' v. NULL:
>
> [Quote From Oracle SQL Reference]
> Oracle partially supports these subfeatures:
>
> E021-02, CHARACTER VARYING data type (Oracle does not distinguish a
> zero-length VARCHAR string from NULL)
> E021-03, Character literals (Oracle regards the zero-length literal ''
> as being null)
> [/Quote From Oracle SQL Reference]
>
> I'm with SQL:1999 on this. (Quite what your OO code has to do with
> the meaning of NULL in SQL still mystifies me).

Actually Oracle does conform to the standard. Some other products do not, by default, but have a parameter setting to make themselves like Oracle so that they can claim ANSI compliance.

See Tom Kyte's discussion of this in Chapter 1 of "Expert one-on-one Oracle."

--
Daniel Morgan
http://www.outreach.washington.edu/extinfo/certprog/oad/oad_crs.asp
damorgan_at_x.washington.edu
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