data a; set b; if jiaoyi='交易成功';
proc sort data=a; by cnum time1;
proc freq data=a; tables cnum /out=a1;
data a2; set a1; k=0; do while(k<count); output; k+1; end;
data b; set a2; keep count;
data b1; merge b a;
data b2; set b1; if count>3; drop count;
run;
cnum time1 是什么意思