程序是这样的：
data _null_;
set research.investment;
format invtime 8.0;
a='%roundcount(';
b=',';
c=')';
file "roundnumber.txt";
put a $ institution $ b $ invtime  c $;
run;
proc sql noprint;
create table round
(institution char(12),invtime num,round num);
%macro roundcount(institution,date);
select count(*) into :count
from research.investment
where institution="&institution" and invtime<&date;
insert into round(institution,invtime,round) values ("&institution",&date,&count);
%mend;
%include"roundnumber.txt";
quit;

能够运行，但在日志窗口出现了两行：
warning:没有解析符号引用B。