if a and not b in Proc Sql

[lokeshbm]

Hi,

I need the below step in Proc Sql

data newdata;

merge dset1(in=a) dset2(in=b);

by subjid visit location pin;

if a and not b;

run;

[LinusH]

This must be the oldest SAS question. The are literally thousands of papers and have been discussed Om this forum several times. Do a search her and on support.Sas.com.
Short answer : left join, but it depends on your data.