Re: "= null" & "is null"

From: Norris <johnnie_at_cooper.com.hk>
Date: 27 Aug 1999 04:22:24 GMT
Message-ID: <7q53q0$15si$1@adenine.netfront.net>

If I use nvl(column_a,'XYZ') = 'XYZ' in the where clause to find only null value, then I will also select rows where column_a = 'XYZ' although the chance of having value = 'XYZ' is little.

Samuel Leung <m2624526_at_netvigator.com> wrote:
> Remember the concept that Null is never 'EQUAL' to everything, even itself.
> So, = NULL means nothing
> If you compare two values, say a = b, and the two values are nullable, use
> Nvl() function

> Norris wrote in message <7q3936$37f$2_at_imsp009a.netvigator.com>...

>>What is the difference between = null and is null?
>>
>>--
>>--
>>http://www.washington.edu/pine/faq/

--
Have several nice days...

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Received on Thu Aug 26 1999 - 23:22:24 CDT