Re: sql comparison between records

Hey. Good question.

At first blush:

select a.key, avg(a.ts - (select min(b.ts) from theFile b where b.ts > a.ts
and a.key = b.key)) from theFile a group by a.key

but I can all but guarantee that that won't work.

Maybe with a common table expression or a view....

signed, pondering in pennsylvania....   ;-)


===========================================================
R. Bruce Hoffman, Jr.
 -- IBM Certified Specialist - AS/400 Administrator
 -- IBM Certified Specialist - RPG IV Developer

"America is the land that fought for freedom and then
  began passing laws to get rid of it."

     - Alfred E. Neuman

-----Original Message-----
From: Joel Fritz <JFritz@sharperimage.com>
To: MIDRANGE-L@midrange. com (E-mail) <MIDRANGE-L@midrange.com>
Date: Friday, July 20, 2001 1:20 PM
Subject: sql comparison between records


>How do you do this in SQL?
>
>I have a file ordered by key value and a timestamp.  There are multiple
>records for each key value. I want to find the difference between time
>stamps of successive records and calculate the average difference for a key
>value group.  I know, it's easy in RPG.  I'm not trying to measure
>programmer productivity. <g>
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