I think this is what you want   data have; input ID Date $ Type delta Bucket; infile datalines missover; datalines; 1234 7-Jul-20 1 1234 14-Jul-20 0 7 1 5656 7-Jul-20 0 5656 14-Jul-20 0 7 8879 7-Jul-20 0 8879 14-Jul-20 1 7 8879 21-Jul-20 0 7 1 ; data want; do until (last.id); set have; by id; if Type = 1 then flag = 1; end; do until (last.id); set have; by id; output; end; run; ... View more

Please post data in usable form using the variable names you are using in the description. ... View more

You can use a WHERE statement or data set option to filter your data. A WHERE statement or the data set option filters can be used in almost every proc in SAS.   Data set option: data input_data_current; set data_file(drop = var1 var2 var3 where=(not missing(ID))); run; WHERE statement data input_data_current; set data_file(drop = var1 var2 var3); where not missing(ID); run; Just a quick comment on terminology "Opening files" could be interpreted in several different ways so it's a very ambiguous term.     @a_zacMD wrote: Hi there, I am using SAS Enterprise Guide.  I am aware there are ways to keep or drop variables when opening new files. For example:    data input_data_current; set data_file (drop=var1 var2 var3);  run;   And I am aware that I can remove rows with missing IDs but can I remove those rows that are missing IDs when I initially open the file?    ... View more

Excellent!   Both single hyphen notation and double hyphen notation are helpful.   You probably know this now, but: Single hyphen works with variables that have a number at the end.  Var1, Var2, Var3, ... Var99. can be referred to as Var1 - Var99. Double hyphen works with variables that are contiguous in the Program Data Vector.  If you run a Proc Contents and use the VARNUM option, the list will be in variable order (not alphabetical order).  If you want a section (or all) of the variables, you can list the first and the last with a -- in between, and SAS will process all variables in between the first specified and the last.  The variables must be contiguous in order for this to work.   Jim ... View more

You can use the following code to create the table you want.     PROC TRANSPOSE data=a out=b prefix=Activity; by id; var activity; RUN; where b is the transposed table and a is the input table.   ... View more