topic Re: Difference Between 2 Data sets in New SAS User

Difference Between 2 Data sets

suzannep — Mon, 05 Aug 2019 16:13:48 GMT

Hi,

I have two data sets. Data set A has 1,000 observations and data set B (subset of data set A) with 800 observations. I want to make a data set C that ONLY has the other 200 observations from data set A.

I'm sure there is some easy code for this but I just don't know what it is. Please help!

Thanks!

Re: Difference Between 2 Data sets

Zad — Mon, 05 Aug 2019 16:25:31 GMT

proc sort data=a;by common_surveyid;

proc sort data=b;by common_surveyid;run;

data a_b;merge a(in=a) b(in=b);

by common_surveyid;

if a and not b;

run;

Re: Difference Between 2 Data sets

Kurt_Bremser — Mon, 05 Aug 2019 17:55:36 GMT

While your code will provide the intended results, it looks horrible.

Compare this;

proc sort data=a;
by common_surveyid;
run;

proc sort data=b;
by common_surveyid;
run;
 
data a_b;
merge
  a (in=a)
  b (in=b)
;
by common_surveyid;
if a and not b;
run;

and tell me, which one is easier to read and understand for another coder?

Re: Difference Between 2 Data sets

Kurt_Bremser — Mon, 05 Aug 2019 17:57:28 GMT

You can also do it in SQL:

proc sql;
create table want as
select a.*
from a
where key not in (
  select b.key from b
);
quit;

Re: Difference Between 2 Data sets

ballardw — Mon, 05 Aug 2019 19:39:31 GMT

Or possibly

Proc Sql;
   create table want as
   select * from tableA
   except
   select * from tableb
  ;
quit;