Date:         Wed, 9 Jan 2008 14:12:18 -0800
Reply-To:     "Nordlund, Dan (DSHS/RDA)" <NordlDJ@DSHS.WA.GOV>
Sender:       "SAS(r) Discussion" <SAS-L@LISTSERV.UGA.EDU>
From:         "Nordlund, Dan (DSHS/RDA)" <NordlDJ@DSHS.WA.GOV>
Subject:      Re: Help with data manipulation. Thanks!!!
In-Reply-To:  <30f27f6b-a1dd-483b-bf3d-029655806fdc@d21g2000prf.googlegroups.com>
Content-Type: text/plain; charset=iso-8859-1

> -----Original Message-----
> From: SAS(r) Discussion [mailto:SAS-L@LISTSERV.UGA.EDU] On
> Behalf Of olivesecret@GMAIL.COM
> Sent: Wednesday, January 09, 2008 1:58 PM
> To: SAS-L@LISTSERV.UGA.EDU
> Subject: Help with data manipulation. Thanks!!!
>
> I have a dataset which include 3 variables: id, i, j. For each id, the
> values for i and j may be 1~4. It is required that the combination of
> these 3 variables to be unique, which means, for example, the
> combination of id=2 i=3 j=1 can be on the dataset for only one time.
> If the combination shows up for two or more times on the datset, I
> need keep only the first obs this combination shows up and remove
> other obs it shows up.
>
> To solve the problem, I sort the dataset according to id i j. Then I
> only need to do iterations within each id. But I do not know how to do
> it by SAS. Can any people help me do it?
>
> Thanks a lot!!!
>
> Olive
>
>
You have received a solution from Toby Dunn using PROC SORT.  If your dataset is already sorted you could use a data step

data want;
  set have;
  by id i j;
  if first.j;
run;

Or you could use PROC SQL

proc sql;
create table want as
  select distinct id, i, j
    from have
   order by id, i, j
   ;
quit;

Hope this is helpful,

Dan

Daniel J. Nordlund
Research and Data Analysis
Washington State Department of Social and Health Services
Olympia, WA  98504-5204