How to output the observations not merged into the first dataset

[Denali]

Hi ,

I merged two datasets using the code below. How do I export or output the IDs and observations in "LOS2" dataset that were not merged into "four" dataset?

data five;
merge four (in=a) LOS2 (keep = ID Admission_date Discharge_date LOS Discharge);
by ID;
if a = 1;
run;

Thank you in advance!

[ballardw]

data five other;
   merge four (in=a) 
              LOS2 (keep = ID Admission_date Discharge_date LOS Discharge);
    by ID;
    if a = 1 then output five;
    else output other;
run;

You need to 1) specify another data set on the Data statement, 2) conditionally indicate which specific data set using OUTPUT statements which data set each group of records gets written to.

[SASKiwi · Accepted solution]

data five;
merge four (in=a) 
           LOS2 (in = b keep = ID Admission_date Discharge_date LOS Discharge);
by ID;
if b and not a;
run;