[Oracle] ORDER BY, HAVING, ALIAS, GROUP FUNCTION 연습

ORDER BY == SORTING SELECT FROM WHERE ORDER BY SELECT ENAME, SAL FROM EMP ORDER BY SAL ASC; --오름차순 정렬 SELECT ENAME, SAL FROM EMP ORDER BY SAL DESC; --내림차순 정렬 --ALIAS SELECT EMPNO, ENAME, SAL * 12 AS annsal FROM EMP ORDER BY annsal DESC; --ALIAS 로도 사용 가능하다. SELECT ENAME, COMM FROM EMP ORDER BY COMM NULLS LAST; --NULLS FIRST NULL값이 맨 위로 올라온다. // NULLS 의 default 값은 LAST SELECT EMPLOYEE_ID, JOB_ID, ..