Re: Oracle 7.1 Enhancements
Date: 22 Jun 1994 18:46:37 -0600
Message-ID: <2uam1d$9gh_at_u.cc.utah.edu>
Michael Sallwasser wrote:
>
>Let us say we want a list of employees whose commission for the week
>is over $400, and another list of employees whose commision is less
>than or equal to $400. Since commission is an illogical or not applicable
>concept for non-sales people, people who aren't sales people should logically
>not appear in either list. And, as I understand it, by the rules of ANSI SQL,
>they would not.
>
I agree with the rules of ANSI SQL for > and <. It is <> that I have a hard
time with.
Select * from employee where commission <> 400.00
should return all the employees that do not have a commission of $400.00,
NOT all employees who have a commission that is not 400.00 as defined
by ANSI SQL.
A better example: You want to query all the employees that may live out of Nebraska.
You have to use Select * from employee where nvl(state,'ZZ') <> 'NB'; instead of Select * from employee where state <> 'NB';Received on Thu Jun 23 1994 - 02:46:37 CEST