ALTER TABLE "테이블명" ADD ("컬럼명" "데이터타입" ("데이터크기"));
ALTER TABLE "테이블명" MODIFY ("컬럼명" "데이터타입" ("데이터크기"));
ALTER TABLE "테이블명" DROP COLUMN "컬럼명";
ALTER TABLE "테이블명" RENAME COLUMN "현재컬럼명" TO "바꿀컬럼명";