Re: [GENERAL] null and =

Slavica Stefic wrote:

> is null = null true or also null?

A null value represents either the absence of data or
an unknown value. A null value is not
the same as a zero or a blank.

Thus two tuples with null values are never the same and can not
be joined.

> it appears that two null records are not equal if they are both null.
> First question: is this correct? is this SQL conformant?

yes

> 2: if I change the sources for the operator to compare nulls as
> they where values
> will it have too many side effects?

Don't do that. You will get a desaster ;-)

Herbie

--
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Herbert Liechti E-Mail: Herbert(dot)Liechti(at)thinx(dot)ch
ThinX networked business services Stahlrain 10, CH-5200 Brugg
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~