Calling a macro variable from libname

Question

How do I call a macro variable in the from clause of proc sql if I wish to use it in a libname? Let me show you what I mean:

options nofmterr;
libname FRST "/ecm/retail/mortgage/nbk6kra/LGD/data/frst_201312bkts";
libname HELN "/ecm/retail/mortgage/nbk6kra/LGD/data/heln_201312bkts";
libname HELC "/ecm/retail/mortgage/nbk6kra/LGD/data/helc_201312bkts";

%let pathLGD = /new/mortgage/2014Q4/LGD;
%let prod = FRST; 

/**************** Segment calculation **************** Date filter to be consistent with model documentation for segmented tables****************/

%macro Performance(prod);

proc sql;
create table lgd_seg_&prod as 
select distinct
SegDT_LGD_2013,
min(ScoreDT_LGD_2013) as min_range,
max(ScoreDT_LGD_2013) as max_range,
count(*) as count,
mean(lgd_ncl_adjusted) as LGD_actual, 
mean(ScorePIT_LGD_2013) as LGD_pred_pit_1, 
mean(ScoreDT_LGD_2013) as LGD_pred_dt_1
from "&prod."scored;
where coh_asof_yyyymm > 200612
group by 1;
quit;

PROC EXPORT DATA=lgd_seg_&prod._fs
                OUTFILE= "&pathLGD./lgd_seg.xlsx" 
                DBMS=XLSX REPLACE;
         SHEET="&prod._lgd_seg_fs"; 
    RUN;

%mend;

%Performance(prod=FRST);        
%Performance(prod=HELN);        
%Performance(prod=HELC);

So in the "from" clause, the macro is supposed to read FRST.scored, HELN.scored, and HELC.scored respectively. Currently it cannot find the file, and if I were to remove the quotation marks, then it'd become "work.FRSTscored". I hope I've made this clear. Any input and comment is appreciated.

Answer 1

When you want to follow the the resolved value of a macro variable with an immediate additional character you should escape the macro variable with a full stop (.). For example:

%let start = one;
%put &start.two;
%put &start..two;
%put &startend;

onetwo
one.two
WARNING: Apparent symbolic reference STARTEND not resolved.

So your code should read from &prod..scored;.

---

If you ever need to you can also delay the resolution of a macro variable with double ampersand (&&):

%let end = two;
%let onetwo = three;
%put &&one&end;
%put &&&start&end;

Three
Three

Or:

%let three = inception;
%put &&&&&&&start&end;

inception