[프로그래머스] SQL고득점킷 _ SUM, MAX, MIN

1.

-- 코드를 입력하세요
SELECT DATETIME
FROM ANIMAL_INS
ORDER BY DATETIME DESC
LIMIT 1

 

2. 

-- 코드를 입력하세요
SELECT DATETIME
FROM ANIMAL_INS
ORDER BY DATETIME ASC
LIMIT 1

 

3. 

-- 코드를 입력하세요
SELECT COUNT(*)
FROM ANIMAL_INS

 

4.

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

-- 코드를 입력하세요
SELECT COUNT(p.name)
FROM (SELECT DISTINCT NAME
      FROM ANIMAL_INS) p