How to combine two datasets into one in SAS - merge

Question

I have some SAS code from my editor here. I am learning to use SAS (this is my first time using it), so I'm not sure how much code is relevant.
proc import
datafile="C:\Users\barnedsm\Desktop\SAS\ToothGrowth.csv"
dbms=csv
out=tooth;
proc print data=tooth (obs=5);
run;
6. create two SAS data sets ToothGrowth_OJ and ToothGrowth_VC for the animals with the
delivery method orange juice and ascorbic acid, respectively. (5 points)
data ToothGrowth_OJ;
set tooth;
where (supp="OJ");
proc print data=ToothGrowth_OJ (obs=5);
run;
data ToothGrowth_VC;
set tooth;
where (supp="VC");
proc print data=ToothGrowth_VC (obs=5);
run;
7. save the two SAS data sets in a permanent folder on your computer. (5 points)
libname mylibr "C:\Users\barnedsm\Desktop\SAS";
data mylibr.ToothGrowth_OJ_permanent;
set ToothGrowth_OJ;
run;
libname mylibr "C:\Users\barnedsm\Desktop\SAS";
data mylibr.ToothGrowth_VC_permanent;
set ToothGrowth_VC;
run;
For the final question on my assignment, I am wanting to re-combine the last two datasets I made (ToothGrowth_OJ and ToothGrowth_VC) into one dataset (ToothGrowth_combined). How would I do this? My thoughts would be to use a subset function like I used to separate the two. The code I have in mind is below.
data ToothGrowth_combined;
set ToothGrowth_OJ(where=(supp="OJ"));
keep supp Len;
run;
This would tell SAS to keep the values from the ToothGrowth_OJ dataset that have OJ in the "supp" columns (which is all of them) and to keep the variable Len. Assuming that I have done this code correctly, I want to add in the values from my ToothGrwoth_VC dataset in a similar way, but the output is an empty dataset when I run the same code, but replace the "ToothGrowth_OJ" with "ToothGrowth_VC". Is there a way to use the subset code to take these two separate datasets and combine them into one, or an easier way?

Answer 1

Your starting code is doing these steps.
Using PROC IMPORT to guess how to read text file into a dataset.
Creates a subset of the data with only some of the observations.
Creates a second subset of the data.
To recombine the two subsets use the SET statement and list all of the input datasets you want. To limit the number of variables written to the output dataset use a KEEP statement.
data ToothGrowth_combined;
set ToothGrowth_OJ ToothGrowth_VC ;
keep supp Len;
run;
I am not sure why you added the WHERE= dataset option in your code attempt since by the way they were created they each only have observations with a single value of SUPP.
If you want to combine the permanent datasets instead (for example if you started a new SAS session with an empty WORK library) then use those dataset names instead in the SET. Just make sure the libref that points to them is defined in this SAS session.
libname mylibr "C:\Users\barnedsm\Desktop\SAS";
data ToothGrowth_combined;
set mylibr.ToothGrowth_OJ_permanent mylibr.ToothGrowth_VC_permanent;
keep supp Len;
run;