-- Create temp table for Person and load data into temp table IF OBJECT_ID('tempdb..#person') IS NOT NULL DROP TABLE #person CREATE TABLE #person ( pk_person INT IDENTITY(1,1) NOT NULL ,id_number NCHAR(27) NOT NULL  )  -- s- source table  -- d- destination table  MERGE  #person AS d   USING (SELECT m.id_number  . . FROM      WHEN NOT MATCHED AND  s.id_number IS NOT NULL  THEN  INSERT   WHEN MATCHED AND  (d.prfscid_code != s.prfscid_code   THEN   UPDATE SET d.prfscid_code=s.prfscid_code    WHEN MATCHED AND s.id_number IS NULL  THEN  DELETE  ;