SAS Find Top Combinations in Dataset -

hell --

i have sales data looks this:

data have;   input order_id item $; cards; 1 1 b 2 2 c 3 b 4 4 b ; run; 

what i'm trying find out popular combinations of items ordered. example in above case, there 2 orders contained items a&b, 1 order of a&c, , 1 order of b. best way output different combinations along numbers of orders placed?

it seems there no permutation issue, try this:

proc sort data=have; order_id item; run;  data temp;   set have;   order_id;   retain comb;   length comb $4;   comb=cats(comb,item);   if last.order_id do;      output;      call missing(comb);   end; run;  proc freq data=temp;    table comb/norow nopercent nocol nocum; run;