Setting Macro Variable equal to value in table - sas

Question

I have a table with one row and 4 columns. I would like to create 4 macro variables named after each column where the value is set to the value in the 1 row.
If this were R I could access the values directly with something like:
newvar1=tablename[1,1]
newvar2=tablename[1,2]...
Is there anyway for me to select values from a table and set macrovariables equal to that value?
So something like:
%macrovar1=tablename[1,1]...
Except obviously the right side of the equals sign is R code not SAS.
Thanks

Answer 1

You can use proc sql to do it like so:
proc sql noprint inobs=1;
select name into :my_val from sashelp.class;
quit;
%put &my_val;
Or you can use call symput from the datastep like this:
data _null_;
set sashelp.class(obs=1);
call symput('my_val',name);
run;
For something more flexibile, we use a utility macro that allows us to check values from anywhere in our code. I've modified it slightly to accommodate your request but the usage will be like this:
%let my_val = %get_val(iDs=sashelp.class, iField=name);
You could also use it in the middle of a proc or a datastep like so:
data _null_;
my_value = "%get_val(iDs=sashelp.class, iField=name)";
run;
Or even:
proc sql noprint;
create table want as
select * from sashelp.class
where name = "%get_val(iDs=sashelp.class, iField=name)"
;
quit;
Here is the macro definition:
%macro get_val(iDs=, iField=);
%local dsid pos rc result cnt value;
%let result=;
%let cnt=0;
/*
** ENSURE ALL THE REQUIRED PARAMETERS WERE PASSED IN.
*/
%if "&iDs" ne "" and "&iField" ne "" %then %do;
%let dsid=%sysfunc(open(&iDs,i));
%if &dsid %then %do;
%let pos=%sysfunc(varnum(&dsid,&iField));
%if &pos %then %do;
%let rc=%sysfunc(fetch(&dsid));
%if "%sysfunc(vartype(&dsid,&pos))" = "C" %then %do;
%let value = %qsysfunc(getvarc(&dsid,&pos));
%if "%trim(&value)" ne "" %then %do;
%let value = %qtrim(&value);
%end;
%end;
%else %do;
%let value = %sysfunc(getvarn(&dsid,&pos));
%end;
&value
%end;
%else %do;
%put ERROR: MACRO.GET_VAL.SAS: FIELD &iField NOT FOUND IN DATASET %upcase(&iDs).;
%end;
%end;
%else %do;
%put ERROR: MACRO.GET_VAL.SAS: DATASET %upcase(&iDs) COULD NOT BE OPENED.;
%end;
%let rc=%sysfunc(close(&dsid));
%end;
%else %do;
%put ERROR: MACRO.GET_VAL.SAS: YOU MUST SPECIFY BOTH THE IDS AND IFIELD PARAMETERS TO CALL THIS MACRO.;
%end;
%mend;
The above macro is an abbreviated version of the %ds2list macro found here.

Answer 2

There are several ways, but the simplest is:
data _null_;
set have;
if _n_=1 then do;
call symputx('macrovar1',var1);
*more of these;
end;
stop;
run;
That opens the dataset, then if on first row (_n_ is iteration of data step loop, which in most cases is the first row), use call symputx to assign its value to a macro variable.
I would note that you should remember that SAS macro variables are not data variables, do not have a data type (always are text), and usually are not used to store data the way you would use vectors in R.