Re: Char vs Varchar2 and NULL

C. Broom a écrit:

> In article <1998090902372200.WAA05083_at_ladder01.news.aol.com>,
> Jpmakar <jpmakar_at_aol.com> wrote:
> >Beware the Oracle NULL. It does not mean 'NULL', it means 'undefined'. I am
> >told but have not checked, that
> >
> >IF NULL = NULL THEN
> >
> >will always evaluate to false for the above reason.
>
> The word 'NULL' in a database means 'undefined' value. If my age is
> set to NULL and your age is also set to NULL then it makes sense that
> my age should not be considered to be equal to your age.
> In other words, neither my age nor yours is known so no statement can
> be made about their equality or lack thereof.
>
> In a database NULL = NULL is never true,
> just as NULL != NULL is never true.

To be precise, either of the two evaluates to NULL! In an expression, a final value of NULL would
be considered as FALSE. Received on Fri Sep 11 1998 - 04:10:53 CDT