SASでSQLのgroup_concat的なことをやる

group_concat.sas

/*https://communities.sas.com/t5/SAS-Enterprise-Guide/How-to-use-GROUP-BY-to-concatenate-strings-in-SAS-proc-SQL/td-p/208967*/
data want (drop=string_old);
set tmp (rename=(string=string_old));
by id;
retain string;
length string $ 20; * set large enough to accommodate the maximum number of records per ID;
if first.id then string = '';
string = catx(',',trim(string),string_old);
if last.id then output;
run;

group_concat2.sas

data original(index=(Cust_no));
input Cust_no Prod $ ACC_flag $ Bal $ ;
datalines;
111    a1    qaz    10
111    b1    wsx    11
222    c1    wsx    233
333    d1    grw    251
444    e1    dc    25
444    f1    vefw    1231
444    g1    wefr    36
555    h1    bdfgh    615
666    i1    qe    767
777    j1    erg    31
777    k1    eth    472
777    l1    ret    251
777    m1    dfwef    3761
888    p1    ffef    36
run;
proc sort data=original(keep=cust_no) out=customers nodupkey;
by Cust_no;
run;
data new;
set customers;
length Prod_con Acc_con $50;
do until (_iorc_ ne 0);
   set original key = Cust_no;
   if _iorc_ = 0 then do;
     Prod_con = CATX('|',Prod_Con,Prod);
     Acc_con = CATX('|',Acc_con,Acc_flag);
   end;
end;
output;
_iorc_ = 0; _error_=0;
run;
proc print;