Solved

SQL Query to display duplicates ?

Posted on 2016-11-22
6
39 Views
Last Modified: 2016-11-23
Hi,
I have a table of Customers.  In some cases the names are the same for various customer ID's.  For example (see below),  Clinton is attached to 3 customers:
CUSTID  NAME
------|----------
39    | Carter   
40    | Reagan   
41    | Carter     
42    | Clinton  
44    | Clinton    
45    | Clinton

Open in new window

I would like to write a query that will give me a list of the duplicates (and only the duplicates) ordered by name, with a result something like:
CUSTID  NAME
------|----------
39    | Carter   
41    | Carter     
42    | Clinton  
44    | Clinton    
45    | Clinton 

Open in new window

Any suggestions?
0
Comment
Question by:Rob Rudloff
6 Comments
 
LVL 15

Accepted Solution

by:
mcmonap earned 250 total points
ID: 41897936
In it's simplest form something like this:
SELECT
	*
FROM
	customers
WHERE
	[name] IN(
		SELECT
			[Name]
		FROM
			customers
		GROUP BY
			[name]
		HAVING
			COUNT(1) > 1)

Open in new window

0
 

Author Comment

by:Rob Rudloff
ID: 41898108
Ah yes -- I always forget about HAVING and then when I remember it, I can't seem to make it work.  (I'll read up on it)  
I will employ your suggestion.  Thanks!  
(I found another example using a join to the same table.  If I can get that to work, I'll post it here.)
0
 
LVL 25

Assisted Solution

by:Pawan Kumar
Pawan Kumar earned 250 total points
ID: 41898227
Try this ...easiest one..

--

SELECT * FROM 
(
       SELECT * , COUNT(*) OVER (PARTITION BY name) rnk FROM customers
)k
WHERE rnk > 1

--

Open in new window


Hope it helps !
0
3 Use Cases for Connected Systems

Our Dev teams are like yours. They’re continually cranking out code for new features/bugs fixes, testing, deploying, testing some more, responding to production monitoring events and more. It’s complex. So, we thought you’d like to see what’s working for us.

 
LVL 32

Expert Comment

by:awking00
ID: 41899551
What dbms (and version) are you using?
0
 

Author Comment

by:Rob Rudloff
ID: 41899748
This is SQL Server 2008 R2.
0
 

Author Closing Comment

by:Rob Rudloff
ID: 41899752
Thanks!
I will work with both solutions, so that I can understand -- I am new-ish to SQL and want to learn from these examples you've posted.
0

Featured Post

Is Your Active Directory as Secure as You Think?

More than 75% of all records are compromised because of the loss or theft of a privileged credential. Experts have been exploring Active Directory infrastructure to identify key threats and establish best practices for keeping data safe. Attend this month’s webinar to learn more.

Question has a verified solution.

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

Confronted with some SQL you don't know can be a daunting task. It can be even more daunting if that SQL carries some of the old secret codes used in the Ye Olde query syntax, such as: (+)     as used in Oracle;     *=     =*    as used in Sybase …
If you have heard of RFC822 date formats, they can be quite a challenge in SQL Server. RFC822 is an Internet standard format for email message headers, including all dates within those headers. The RFC822 protocols are available in detail at:   ht…
This Micro Tutorial will give you a basic overview how to record your screen with Microsoft Expression Encoder. This program is still free and open for the public to download. This will be demonstrated using Microsoft Expression Encoder 4.
Sending a Secure fax is easy with eFax Corporate (http://www.enterprise.efax.com). First, just open a new email message. In the To field, type your recipient's fax number @efaxsend.com. You can even send a secure international fax — just include t…

863 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

22 Experts available now in Live!

Get 1:1 Help Now