You can subset your first data: Data Data_A; Set Data_Have; Where code = “A”; Run; Example: Data_A ID VID Code CodeA 1 5 A 1 2 6 A 1 After that use proc sql to assign a new flag as you want: Proc sql noprint; Create table Data_A_want as Select *, case when VID in (select distinct VID from Data_A) then 1 end else 0 as VID_ CODEA From Data_Have; Quit; The above code should give you the flag you want.
... View more