[2 days left] What’s wrong with your cloud strategy? Learn why multicloud solutions matter with Nimble Storage.Register Now

x
?
Solved

Compare values from the most recent row to the one just before it

Posted on 2013-01-28
2
Medium Priority
?
329 Views
Last Modified: 2013-01-29
Hi all,

A table has a timestamp t, and some numeric column, n

I need sql statement that would compare n from the row where t is max [max(t)] to:
 the value of n in the row where t is right before max(t)
-- OR --
 the value of n in the row where t is the second before max(t)

To clarify:
t                                           n
2013-01-28 19.00.00           23
2013-01-28 19.00.01           88
2013-01-28 19.00.02           2
2013-01-28 19.00.03           3


I need sql statement that would compare 3 to:
 2
-- OR --
 88

Any help is appreciated
0
Comment
Question by:darrgyas
[X]
Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
2 Comments
 
LVL 37

Accepted Solution

by:
momi_sabag earned 2000 total points
ID: 38829332
You need to generate row numbers and then join to yourself

With a as ( select row_number() over (order by t desc) as row , n from hourtable)
Select t1.n, t2.n
From a t1 join a t2 on t1.rown=t2.rown+1
0
 

Author Closing Comment

by:darrgyas
ID: 38831063
thank you
0

Featured Post

Important Lessons on Recovering from Petya

In their most recent webinar, Skyport Systems explores ways to isolate and protect critical databases to keep the core of your company safe from harm.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Recursive SQL in UDB/LUW (you can use 'recursive' and 'SQL' in the same sentence) A growing number of database queries lend themselves to recursive solutions.  It's not always easy to spot when recursion is called for, especially for people una…
Recursive SQL in UDB/LUW (it really isn't that hard to do) Recursive SQL is most often used to convert columns to rows or rows to columns.  A previous article described the process of converting rows to columns.  This article will build off of th…
In this video, Percona Solution Engineer Dimitri Vanoverbeke discusses why you want to use at least three nodes in a database cluster. To discuss how Percona Consulting can help with your design and architecture needs for your database and infras…
Want to learn how to record your desktop screen without having to use an outside camera. Click on this video and learn how to use the cool google extension called "Screencastify"! Step 1: Open a new google tab Step 2: Go to the left hand upper corn…

656 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question