Re: Why using "Group By"

oferbu wrote:
> This is a theoretical question. Why do I need to add the "Group By" in
> the following SQL:
>
> SELECT
> CUSTOMER_CITY, COUNT(*)
> FROM
> CUSTOMER_TABLE
>
> Isn't it clear that I want to get the number of rows per city, so why
> is it necessary to add:
>
> GROUP BY
> CUSTOMER_CITY
How will you write (using your sintax) something like this:

SELECT
   CUSTOMER_CITY, COUNT(*)
FROM
   CUSTOMER_TABLE
GROUP BY
   CUSTOMER_CITY, SOME_OTHER_CUSTOMER_TABLE_ATTRIBUTE

-- 
Regards,
Damjan S. Vujnovic

University of Belgrade
School of Electrical Engineering
Department of Computer Engineering & Informatics
Belgrade, Serbia

http://galeb.etf.bg.ac.yu/~damjan/