Solved

Access 2007 - How do I count unique ID's

Posted on 2010-09-19
8
950 Views
Last Modified: 2012-05-10
I have a table with two columns of data.

Account ID
Contact ID

Please provide me with the SQL statement to use in Access 2007 to output a new table where each account ID appears only once and in the second column there is a column indicating the number of unique contact ID's for each account.
0
Comment
Question by:rporter45
8 Comments
 
LVL 44

Expert Comment

by:GRayL
ID: 33712437
SELECT AccountID, Count(ContactID) as CountOfContacts FROM myTable GROUP BY AccountID;
0
 
LVL 119

Accepted Solution

by:
Rey Obrero earned 500 total points
ID: 33712440
select [Account ID], count([contact ID])
from tablex
group by [account ID]
0
 

Author Closing Comment

by:rporter45
ID: 33712451
This one provided the exact syntax.
0
U.S. Department of Agriculture and Acronis Access

With the new era of mobile computing, smartphones and tablets, wireless communications and cloud services, the USDA sought to take advantage of a mobilized workforce and the blurring lines between personal and corporate computing resources.

 
LVL 44

Expert Comment

by:GRayL
ID: 33712453
Oops:

SELECT a.AccountID Count(a.ContactID) AS CountUniqContacts FROM (
SELECT DistinctROW AccountID, ContactID FROM myTable) AS a GROUP BY a.AccountID;
0
 
LVL 47

Expert Comment

by:Dale Fye (Access MVP)
ID: 33712457
Well, if your current structure allows you to have multiple records with the same accountID and ContactID, then neither of the above will work.  You will first need to get DISTINCT combinations of AccountID and ContactID, so try:

SELECT T.[Account ID], Count(T.[Contact ID]) as UniqueContacts
FROM (SELECT DISTINCT [Account ID], [Contact ID] FROM your Table) as T
GROUP  BY T.[Account ID]
0
 
LVL 44

Expert Comment

by:GRayL
ID: 33712458
I believe you selected answer will count multiple ContactID's.
0
 
LVL 44

Expert Comment

by:GRayL
ID: 33719434
I have run tests and fyed's solution at http:#a33712457 is correct.  My solution in the previous post is not correct as I used DISTINCTROW instead of DISTINCT.
0

Featured Post

Enterprise Mobility and BYOD For Dummies

Like “For Dummies” books, you can read this in whatever order you choose and learn about mobility and BYOD; and how to put a competitive mobile infrastructure in place. Developed for SMBs and large enterprises alike, you will find helpful use cases, planning, and implementation.

Question has a verified solution.

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

Suggested Solutions

Title # Comments Views Activity
count unique records in access report 2 23
Field behavior for "locked" form 12 29
Cross Tab with two column values 7 32
Operation must use an updatable query 4 24
When you are entering numbers in a speadsheet, and don't remember what 6×7 is, you just type “=6*7" instead. It works in every cell! This is not so in Access. To enter the elusive 42 in a text box, you have to find a calculator, and then copy the re…
A simple tool to export all objects of two Access files as text and compare it with Meld, a free diff tool.
Learn how to number pages in an Access report over each group. Activate two pass printing by referencing the pages property: Add code to the Page Footers OnFormat event to capture the pages as there occur for each group. Use the pages property to …
With Microsoft Access, learn how to start a database in different ways and produce different start-up actions allowing you to use a single database to perform multiple tasks. Specify a start-up form through options: Specify an Autoexec macro: Us…

911 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

Need Help in Real-Time?

Connect with top rated Experts

25 Experts available now in Live!

Get 1:1 Help Now