Date:         Mon, 1 May 2000 17:04:07 -0400
Reply-To:     "Roberson, Sheryll" <RobersonS@AETNA.COM>
Sender:       "SAS(r) Discussion" <SAS-L@LISTSERV.UGA.EDU>
From:         "Roberson, Sheryll" <RobersonS@AETNA.COM>
Subject:      Re: Get duplicate records?

Another solution is:

Data MyData;
  set MyData;
  id_class = compress(id||class);

proc sort data=MyData;
  by id_class;


Data MyData2;
 Set MyData;
  By id_class;
   If not(first.id_class) or not(last.id_class)
      then output;



   Sheryll Roberson
  U.S. Quality Algorithms-Houston
   Strategic Healthcare Analysis

> *  713-350-2874
> * RobersonS@Aetna.com


-----Original Message-----
From: David L. Ward [mailto:dward@SASHELP.COM]
Sent: Monday, May 01, 2000 3:48 PM
To: SAS-L@LISTSERV.UGA.EDU
Subject: Re: Get duplicate records?


Here's the simplest way in my humble opinion (aka IMHO)

proc sort data=MyData;
  by id class;
data MyData2;
  set MyData;
  by id class;
  if first.class+last.class<2;
run;

Unique records have first.class and last.class equal to 1, all non-unique
records have something else (like first.class=0, last.class=1, or both zero,
etc.).  So testing if the first and last indicator variables sum to 2 gives
you non-unique records by class.

HTH
David Ward
SASHelp.com (soon to be libname.com)



-----Original Message-----
From:    Kathy White <kathyzhi@HOTMAIL.COM>
Sent:    5/1/00 7:03:20 PM
Subject: Get duplicate records?

> Suppose I have following dataset: MyData:
>
>ID   Class  grade
>001   100    A
>001   200    B
>001   300    A
>002   100    A
>002   100    B
>002   200    C
>003   100    A
>003   200    B
>003   300    A
>
>Right now, what I want to select is those who attened the same class twice.
>In this example, I want to get the student with ID=002. What is the most
>efficient way to do this? Any advice is appreciated in advance.
>Regards,
>Kathy
>
>
>________________________________________________________________________
>Get Your Private, Free E-mail from MSN Hotmail at http://www.hotmail.com
>

_____________________________________________________
Sent by SASHelp.com user David L. Ward
SASHelp.com - On-Line SAS Resources
Web interface to SAS-L at http://www.sashelp.com/sasl