SELECT 실행순서 이해하기

SELECT
NVL(NAME, '아무개')
,NVL(KOR,0)
,NVL(ENG,0)
,NVL(MATH,0)
FROM
SAMPLE
ORDER BY NAME; -- 이렇게 하면

SELECT
NVL(NAME, '아무개') AS STU_NAME
,NVL(KOR,0)
,NVL(ENG,0)
,NVL(MATH,0)
FROM
SAMPLE
ORDER BY STU_NAME; -- 이렇게 하면

![](https://velog.velcdn.com/images/eeunnii/post/4987e429-8e2a-44c9-b10c-b05ac5d5069e/image.png)

SELECT
ROUND(145.45) --- 145
,ROUND(145.45, 1)--145.5
,ROUND(145.45, -1) -- 150 이거 왜 반올림
FROM
DUAL;