So SAS equality tests will match missing values (of the same type of missing value).  So . will match . but not match .A or any actual number. If you want exclude those then just add an additional condition.  Just test if one of the two values is missing should be enough. select * from A left join B on a.id = b.id and not missing(a.id) ; ... View more

Is the variable character or numeric? This can be important as when you use character functions, such as the PRX functions, then SAS does an automatic conversion from the numeric to character that likely is not going to result in the actual desired character string before "counting" or matching.   If the variable is actually character than the LENGTH function will return the number of characters though may count any leading spaces. So actual examples of your data and complete code plus what you expect might be helpful in diagnosing what is going on. ... View more

This is also helpful. Thanks Chris. I am used to DI Studio which relies much more heavily on metadata...seems like a different approach will be better here 🙂 ... View more