SAS Macro variable to represent what is in an IN statement in Proc SQL

Question

I have a query I want to run through SAS in Proc SQL where I am getting data from one of our company databases. At the top of the query, for ease of use mostly, I want to be able to put a list of input variables. I am interested in getting data only in certain dates and certain states. The dates I care about are contiguous so I just make a SAS macro variable for the start date and end date and use a between statement. That's easy enough. But, for the states, I can't do such a thing. So, my thought was to do something like

%LET States = ('CT', 'MD', 'ME', 'NC', 'WV');

and then later on, I want to do a where statement

WHERE (State_Tp IN &States)

Now, this does not work. And, I've tried several other variations but I can't seem to get it to work. Is something like this possible?

Answer 1

While your code is fine as is, a better solution (that might have less issues anyway) would be to create a dataset with the desired states, and join against it (or use an exists clause if that is better for your needs). This is easier to maintain (as you can keep the dataset in an easily editable format separate from the code, like in excel) and may be faster in some cases.

data states;
input state_tp $;
datalines;
CT
MD
ME
NC
WV
;;;;
run;

proc sql;
create table test as
select Z.* 
 from sashelp.zipcode Z
 inner join
 states s 
 on z.state_tp=s.state_tp;
quit;

or

proc sql;
create table test as
select * from sashelp.zipcode z
where exists (
  select 1 from states s
   where s.state_tp=z.state_tp);
quit;