query 순서

- 문법 순서 -

SELECT               - 1
FROM                 - 2
WHERE                - 3
GROUP BY             - 4
HAVING               - 5
ORDER BY             - 6

- 실행 순서 -

FROM                 - 1
WHERE                - 2
GROUP BY             - 3
HAVING               - 4
SELECT               - 5
ORDER BY             - 6