SUM, MAX, MIN

https://programmers.co.kr/learn/courses/30/parts/17043

최댓값 구하기

SELECT DATETIME
FROM ANIMAL_INS
ORDER BY DATETIME DESC
LIMIT 1

SELECT max(DATETIME)
FROM ANIMAL_INS

최솟값 구하기

SELECT min(DATETIME)
FROM ANIMAL_INS

동물 수 구하기

SELECT COUNT(ANIMAL_ID)
FROM ANIMAL_INS

중복 제거하기

SELECT COUNT(DISTINCT NAME) AS COUNT
FROM ANIMAL_INS
WHERE NAME IS NOT NULL