Re: migrating from sql server 2000 to oracle 9i-r2

From: DA Morgan <damorgan_at_x.washington.edu>
Date: Thu, 10 Mar 2005 14:23:17 -0800
Message-ID: <1110493200.775293@yasure>

rogergorden_at_gmail.com wrote:

> DA:
>
> Not to start a flame war but you wrote:
>
> 7. NULL means NULL not an empty string
>
> (Which is what I teach in my class) but in another post
>
> Frank van Bortel wrote:
>

>>>I concluded from this that empty string and null in Oracle are one

>
> and
>

>>>the same (at least as far as PLSQL), which is very different that in

>
>

>>>just about every other language.

>
>

>>Right. As documented, as known, as being taught in Oracle Basic
>>SQL, 2nd day, before lunch.

>
>
>

>>Oh - and it's not just PL/SQL, but SQL, too.
>>PEBKAC
>>--
>>Frank van Bortel

>
>
> And your wrote:
>
> In my class it is covered in the first 2nd hour of lecture.
>
> So, am I not getting something or what?
>
> AFAIK:
> NULL != empty string
>
> Perhaps I am mis-understanding the thread.
>
> Roger

In Oracle NULL means NULL. It does not mean an empty string.

In Oracle will return no rows:

SELECT 1 FROM dual WHERE NULL = NULL;
SELECT 1 FROM dual WHERE NULL <> NULL;
SELECT 1 FROM dual WHERE NULL = '';

That is not true in SQL Server with its default configuration.

-- 
Daniel A. Morgan
University of Washington
damorgan_at_x.washington.edu
(replace 'x' with 'u' to respond)

Received on Thu Mar 10 2005 - 16:23:17 CST