RE: Fetch n rows from each group by.

Hi,

I can provide a solution, if you are already on release V5R4. If you are not
yet on release V5R4, I'm not aware of an  easier way than writing and RPG
program with embedded SQL or an stored procedure or UDTF with SQL.

On release V5R4 you may try the following:
with x as (select  Row_Number() over(Partition By Region Order By Sales
Desc) RowNbr,
                   Region, Sales
              From Table
              Where ....) 
Select * from x
   Where RowNbr <= 5; 

Mit freundlichen Grüßen / Best regards

Birgitta Hauser

"Shoot for the moon, even if you miss, you'll land among the stars." (Les
Brown)
"If you think education is expensive, try ignorance." (Derek Bok)
"What is worse than training your staff and losing them?  Not training them
and keeping them!"

-----Ursprüngliche Nachricht-----
Von: midrange-l-bounces@xxxxxxxxxxxx
[mailto:midrange-l-bounces@xxxxxxxxxxxx] Im Auftrag von Mike Pantzopoulos -
(H/O)
Gesendet: Wednesday, February 14, 2007 04:26
An: midrange-l@xxxxxxxxxxxx
Betreff: Fetch n rows from each group by.


I have used the FETCH n ROWS ONLY clause to return the first n records in a
select statement, but I now want to return the first n from each group, and
I'm damned if I can find any reference material for this. Can it be done?

 

In essence I want to return the top 5 agents from each region based on
sales. The following pseudo-SQL would show all the agents in reverse sales
order within region:

 

Select region, sales from file order by region, sales desc

 

If I want to select the first 5 in the entire return set I use:

 

Select region, sales from file order by region, sales desc fetch first 5
rows only

 

How do I write the SQL to return only the first 5 in each region without
having to use RPG?

 

TIA

 


****************************************************************************
*****************************
This email and any files transmitted with it are confidential and intended
solely for the use of the individual or entity to whom they are addressed.
If you are not the intended recipient, any use, disclosure or copying of
this message is unauthorised. If you have received this message in error,
please reply using the sender's email address. 

This footnote confirms that this email message has been scanned for computer
viruses. EIG-Ansvar Limited does not accept liability for any loss or
damage, whether caused by our own negligence or not, that results from a
computer virus or defect in the transmission of this email or any attached
file. 

EIG-Ansvar Limited - Australia (A.B.N. 21 007 216 506)
Email : insure@xxxxxxxxxxxxxxxx

Eig-Ansvar Limited - New Zealand
Email : insure@xxxxxxxxxxxxxxxx

****************************************************************************
*****************************