Solved

Counting in sql

Posted on 2016-09-08
7
59 Views
Last Modified: 2016-09-08
Hi All

I'm trying to do something which might come down to logic, but I think mostly comes down to not knowing how to write it in an sql query.  I've attached a sheet from Excel so that I can explain what I mean.

I need to figure out a way to count the number of different personal_id's per SSN e.g. for THES06001750Y there will be 2.  In my whole data, some may only have one and some could have many, many more.  I need this number so that I can divide into another value later on as it's to do with duplicates.  I can't just do something clever with duplicates because I probably don't know how but mainly because I won't be able to access the other data, summarize both sets of data and track differences in the way I need.

I've had a couple of goes and the best (?!!!!) one so far seems to be to create a table based on distinct personal_id's, get the SSNs and then, in the main table, which has all the first set of data in it, add a column and try to join the tables with some kind of count.  In the vain hope that today might be my lucky day, I tried the following:

UPDATE A SET PI_Counts = B.COUNT (personal_id)
FROM LFRD A LEFT OUTER JOIN LFRD_PI_Count B ON A.SSN = B.PI_SSNs;

I didn't really think it would work and, of course it didn't!

Please can somebody help me figure out a way to do this?

Thanks
Sarah
EE_Count_Example.xlsx
0
Comment
Question by:ScuzzyJo
[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
  • 3
  • 2
  • 2
7 Comments
 
LVL 43

Expert Comment

by:zephyr_hex (Megan)
ID: 41789704
Here's one way to do it:

SELECT  COUNT(personal_id) AS cnt ,
        ssn
FROM    ( SELECT    personal_id ,
                    ssn
          FROM      #tmp_test
          GROUP BY  personal_id ,
                    ssn
        ) c
GROUP BY ssn;

Open in new window


I first get the distinct records from the table (using grouping), then do the count
0
 
LVL 43

Accepted Solution

by:
zephyr_hex (Megan) earned 400 total points
ID: 41789722
And I believe your update will look like:

UPDATE A SET A.PI_Counts = COUNT(c.personal_id)
FROM LFRD A
INNER JOIN (
	SELECT personal_id, ssn
    FROM      #tmp_test
    GROUP BY  personal_id, ssn
) c ON c.ssn = A.ssn
GROUP BY c.ssn

Open in new window

0
 

Author Comment

by:ScuzzyJo
ID: 41789744
Hi Zeyphyr_hex

Thanks, am trying it now, but how do I get the results into a table?  I know I'm going to put "into" somewhere but I'm not sure where.

Thanks
Sarah
0
Complete VMware vSphere® ESX(i) & Hyper-V Backup

Capture your entire system, including the host, with patented disk imaging integrated with VMware VADP / Microsoft VSS and RCT. RTOs is as low as 15 seconds with Acronis Active Restore™. You can enjoy unlimited P2V/V2V migrations from any source (even from a different hypervisor)

 
LVL 29

Assisted Solution

by:Pawan Kumar
Pawan Kumar earned 100 total points
ID: 41789764
Below will insert the result set in to a temp table


SELECT  COUNT(personal_id) AS cnt ,
        ssn
INTO #Temp
FROM    ( SELECT    personal_id ,
                    ssn
          FROM      #tmp_test
          GROUP BY  personal_id ,
                    ssn
        ) c
GROUP BY ssn;

Open in new window

0
 

Author Comment

by:ScuzzyJo
ID: 41789782
Hi

Stupid me!  I knew that - where to put the into bit.

Your solution works perfectly.  Thanks for your help.

Thanks
Sarah
0
 

Author Closing Comment

by:ScuzzyJo
ID: 41789785
Really quick and good answers.  Thanks to both of you.
0
 
LVL 29

Expert Comment

by:Pawan Kumar
ID: 41789790
Welcome :)
0

Featured Post

Get 15 Days FREE Full-Featured Trial

Benefit from a mission critical IT monitoring with Monitis Premium or get it FREE for your entry level monitoring needs.
-Over 200,000 users
-More than 300,000 websites monitored
-Used in 197 countries
-Recommended by 98% of users

Question has a verified solution.

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

This article explains how to reset the password of the sa account on a Microsoft SQL Server.  The steps in this article work in SQL 2005, 2008, 2008 R2, 2012, 2014 and 2016.
JSON is being used more and more, besides XML, and you surely wanted to parse the data out into SQL instead of doing it in some Javascript. The below function in SQL Server can do the job for you, returning a quick table with the parsed data.
Familiarize people with the process of utilizing SQL Server functions from within Microsoft Access. Microsoft Access is a very powerful client/server development tool. One of the SQL Server objects that you can interact with from within Microsoft Ac…
Viewers will learn how to use the UPDATE and DELETE statements to change or remove existing data from their tables. Make a table: Update a specific column given a specific row using the UPDATE statement: Remove a set of values using the DELETE s…

617 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