SAS can merge two data set A, B in different way, A or B, A and B, A not B, Can R merge function do the same way? Thanks -- View this message in context: http://r.789695.n4.nabble.com/Can-merge-function-pick-up-mismatch-part-of-two-data-set-tp2021024p2021024.html Sent from the R help mailing list archive at Nabble.com.