DATA library.final_dataset ;  /*Match-Merge on Ragon_ID for Left-Outter Join */

Merge librarynam.dataset1 (IN=in_1) librarynam.dataset2 (IN=in_2) librarynam.dataset3 (IN= in_3);

BY uniquevar;

IF in_1 = 1 THEN OUTPUT librarynam.final_dataset ; 

RUN;