I have a dataset from a longitudinal study where we collected data by waves. I want to create a new table. I want to keep participants (who are organized by id) who answered all questions (labeled a, b, c, and d) for at least one wave. This was my previous code: proc sql; create table only as select * from full group by id having not (a eq . and b eq . and c eq . and d eq .) order by id, wave; quit; However, with this code, I filter by keeping participants who answered any of these questions by at least one wave. . How can I go about fixing this? ... View more