Re: why the need for is null?

The relational model was designed using a 3 valued logic - true, false,null.

All relational database implementations will inflict this on you :-)

Not everyone is convinced that the 3 valued approach was the best way.
For some entertaining comments by Chris Date and Fabian Pascal see:

http://www.dbdebunk.citymax.com/page/page/622689.htm

best wishes

Mark

Baldur Norddahl wrote:

>Hi,
>
>How come "X=null" is not the same as "X is null"? I got a few selects with
>queries like this:
>
>
>