/*****************************************************************************************************************

SAS file name: Remove_Duplicates.sas
File location: 
_________________________________________________________________________________________________________________

Purpose: To demonstrate how to remove duplicate values in SAS with PROC SORT and PROC SQL.
Author: Peter Clemmensen
Creation Date: 01/11/2017

This program supports the example page "Remove Duplicate Values in SAS" on SASnrd.com

*****************************************************************************************************************/

/* Create example data */
data MyData;
input ID var1-var3;
datalines;
1 1 2 3
1 1 2 3
1 2 3 4
2 1 2 3
2 6 4 2
2 1 2 3
3 2 1 4
4 1 2 1
4 7 4 2
;

/* PROC SQL approach */
proc sql;
	create table NoDuplicates2 as
	select distinct *
	from Mydata;
quit;

/* PROC SORT with NODUPKEY option approach */
proc sort data=Mydata out=NoDuplicates1 nodupkey;
	by _all_; /* Or equivalently by ID var1-var3 */
run;

/* By specific variables */
proc sort data=Mydata out=NoDuplicates1 nodupkey;
	by ID var1;
run;