"NOTE: MERGE statement has more than one data set with repeats of BY values."
SAS Programmer always tries to avoid this message in the log file….because this message means that the resulting data set is probably not what we expected.
Don’t be afraid that there is no way… you can do many-to-many merge using data step. A well known SAS Expert David Franklin points out a way to do many-to-many merge
Many Thanks David!
(Read his original post here)
The Fundamentals of MERGE