标题: SAS程序员测试（二） Try this one. [打印本页] 作者: shiyiming 时间: 2006-4-24 01:08 标题: SAS程序员测试（二） Try this one. proc sort data=tem;
by vol id date;
run;
data test(drop=date);
set tem;
by vol id;
if first.id=1 then do;
Bdate=date;
retain id bdate vol;
end;
if last.id then do;
Edate=date;
output;
end;
format bdate edate yymmdd10.;
run;