topic Re: Count the same observations in two datasets in New SAS User

Count the same observations in two datasets

dapenDaniel — Wed, 22 Jan 2020 22:37:48 GMT

Hi SAS Masters,

I have two dataset. Have1 has 293 observations and Have2 has 246 observations. Both of them only have one variable called "base". I am wondering how many of them are shown in both datasets. I have sorted these two datasets by base. The code I used is below.

data common;
merge have1(in=h1) have2(in=h2);
by base;
if h1 and h2 then output common;
run;

however, the number of observations in "Common" is 258, which is more than the number of observations in Have2 (258 > 246). Did I use the wrong code? Thanks.

Re: Count the same observations in two datasets

novinosrin — Wed, 22 Jan 2020 22:55:12 GMT

Hi @dapenDaniel That means one of the datasets has duplicate values of the same causing one to many join

Re: Count the same observations in two datasets

novinosrin — Wed, 22 Jan 2020 23:12:21 GMT

Consider this example to help you understand better

data one;
input var;
cards;
1
2
3
;

data two;
input var;
cards;
1
1
2
2
2
3
;

data want;
 merge one two;
 by var;
run;

Re: Count the same observations in two datasets

dapenDaniel — Thu, 23 Jan 2020 04:31:10 GMT

Thanks, @novinosrin