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PROC FREQ with nodupkey

Occasional Contributor
Posts: 18

PROC FREQ with nodupkey

[ Edited ]

In proc freq can i use nodupkey....


if it possible means how can i use....


Super User
Posts: 5,876

Re: sas


So in other words,

have a descriptive subject (other than the name of the SW we all are using), and and formulate the question so that your grand parents can understand it. Including sample have and want data.

Data never sleeps
Super User
Posts: 10,209

Re: PROC FREQ with nodupkey

[ Edited ]

First of all, using "sas" as the subject for a question on the SAS forum is, ahem, not very informative.


Second, you seem to misunderstand the use of proc freq. There will only be one line of output (or one observation in the output dataset) for every single value in a given variable counted witrh proc freq, so nodupkey is useless.


If you only want to get a count (or list) of distinct values, do that in SQL:

proc sql;
select distinct sex from sashelp.class;
select count(distinct sex) from sashelp.class;
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Super User
Posts: 23,661

Re: PROC FREQ with nodupkey

Use two PROC FREQs or use DISTINCT in SQL. 


/*This demonstrates how to count the number of unique occurences of a variable
across groups. It uses the SASHELP.CARS dataset which is available with any SAS installation.
The objective is to determine the number of unique car makers by origin/

Note: The SQL solution can be off if you have a large data set and these are not the only two ways to calculate distinct counts.
If you're dealing with a large data set other methods may be appropriate.*/

*Count distinct IDs;
proc sql;
create table distinct_sql as
select origin, count(distinct make) as n_make
group by origin;

*Double PROC FREQ;
proc freq noprint;
table origin * make / out=origin_make;

proc freq data=origin_make noprint;
table origin / out= distinct_freq;

title 'PROC FREQ';
proc print data=distinct_freq;
title 'PROC SQL';
proc print data=distinct_sql;

Super User
Posts: 6,751

Re: PROC FREQ with nodupkey

Just in case it isn't clear from the answers you received, the answer is No.


The only procedure that uses NODUPKEY is PROC SORT.

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