Solved

MS ACCESS - flag duplicates in to the same table

Posted on 2010-11-09
7
1,150 Views
Last Modified: 2012-06-27
(1) My ACCESS Table1 has following columns, i.e., Field1, Field2, Field3, ..., Field 10 with 750,000 records.

(2) FIELD2 is supposed to contain unique value, but somehow there are over 10,000 duplicate values in it. I found this by using

SELECT Table1.FIELD2, count(Table1.FIELD2) as CheckDupe from Table1 group by 1 where CheckDupe>1

QUESTION:
I'd like to find an effective way to
(A) Make Table1 to have extra column FIELD11 as a flag
(B) FIELD11 = "Yes" If FIELD2 contains duplicate value and "No" when it contains unique value?

I am just an intermediate MS ACCESS level.  I found that the following solution would work, but very inefficient ie.,
(i) Make a text list of dupe values in MS WORD "Value1", "Value2", ...., "Value10000"
(ii) Create an intermediate table (called Table2) from Table1 that contain only 2 fields, i.e., FIELD2 and FIELD11, where as FIELD11 = ""
(iii) write an UPDATE query like this:

UPDATE TABLE2 SET TABLE2.FIELD11 = "Yes"
WHERE TABLE2.FIELD2 IN ("Value1", "Value2", ... , "Value1000");

(iv) run this query. then replace the next thousand values, save and run. then redo this again . . . .  until all 10,000 values are covered.

The problem is 1. I have 5 other tables that have the same problem. I dont want to spend the whole week doing this.  So, Help please.
0
Comment
Question by:Paul_ATL
[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
  • 4
  • 3
7 Comments
 
LVL 58

Assisted Solution

by:cyberkiwi
cyberkiwi earned 250 total points
ID: 34097263
Add a new column into Table1 using the UI.
Run this query (if field2 is textual)

update Table1
set Field11 = IIF(DCount("Field2", "Table1", "Field2='" & Field2 & "'")>0,true, false)
0
 

Author Comment

by:Paul_ATL
ID: 34097500
Hi cyberkiwi,

I did as suggested to add FIELD11.
Then Copy-PASTE your query in to an UPDATE querym but when run, it asks me for "parameter entry" of TABLE1
0
 

Author Comment

by:Paul_ATL
ID: 34097556
Hi cyberkiwi,

Sorry, I made some typos.

Your query runs, but when checking the result, it only updates FIELD11 with value -1 for all records.
0
Independent Software Vendors: We Want Your Opinion

We value your feedback.

Take our survey and automatically be enter to win anyone of the following:
Yeti Cooler, Amazon eGift Card, and Movie eGift Card!

 

Accepted Solution

by:
Paul_ATL earned 0 total points
ID: 34097655
Hi cyberkiwi,

I works now. I change >0 to >1
Thanks for your help. Save me lots of time.
0
 
LVL 58

Expert Comment

by:cyberkiwi
ID: 34097665
What type is Field2?

Another approach, make Field11 a Number field, then try this query:

update Table1
set Field11 = DCount("Field2", "Table1", "Field2='" & Field2 & "'")

Actually never mind, I see the error. It should be greater than 1...

update Table1
set Field11 = IIF(DCount("Field2", "Table1", "Field2='" & Field2 & "'")>1,true, false)
0
 
LVL 58

Expert Comment

by:cyberkiwi
ID: 34097685
You're welcome! Makes me happy when askers help themselves :)
0
 

Author Closing Comment

by:Paul_ATL
ID: 34130279
Great advice, just minor issue on >1 instead of >0 but I can figure this out.  But certainly, without his advice, I will NEVER figure to use DCOUNT.

Thanks a bunch
0

Featured Post

Ransomware-A Revenue Bonanza for Service Providers

Ransomware – malware that gets on your customers’ computers, encrypts their data, and extorts a hefty ransom for the decryption keys – is a surging new threat.  The purpose of this eBook is to educate the reader about ransomware attacks.

Question has a verified solution.

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

Did you know that more than 4 billion data records have been recorded as lost or stolen since 2013? It was a staggering number brought to our attention during last week’s ManageEngine webinar, where attendees received a comprehensive look at the ma…
Traditionally, the method to display pictures in Access forms and reports is to first download them from URLs to a folder, record the path in a table and then let the form or report pull the pictures from that folder. But why not let Windows retr…
In Microsoft Access, when working with VBA, learn some techniques for writing readable and easily maintained code.
The viewer will learn how to use the =DISCRINV command to create a discrete random variable, use this command to model a set of probabilities and outcomes in a Monte Carlo simulation, and learn how to find the standard deviation of a set of probabil…

729 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