MERGE INTO :테이블명 USING DUAL ON CONFLICT (:index컬럼명1, :index컬럼명2 /* ...[이하생략] */) 
WHEN MATCHED THEN UPDATE SET 
    :컬럼명1 = :컬럼1의값
    , :컬럼명2 = :컬럼2의값
    /* ...[이하생략] */ 
WHEN NOT MATCHED THEN INSERT (
    :컬럼명1, :컬럼명2 /* ...[이하생략] */
) VALUES (
    :컬럼1의값, :컬럼2의값 /* ...[이하생략] */
);