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

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Herbert Liechti                     E-Mail: Herbert.Liechti@thinx.ch
ThinX networked business services        Stahlrain 10, CH-5200 Brugg
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