SAS - SAS and SQL 对应

1. 组内排序

SQL：

proc sql;
create table data2 as
    select *, row_number() over (partition by id, class, date order by time) as rank
from data;
run;

SAS:

data data2;
set data;
by id class date time;
if first.date then rank=1;else rank+1;
run;