[SQL 공부-프로그래머스] Lv.2 모음 - 1

 

최솟값 구하기

https://school.programmers.co.kr/learn/courses/30/lessons/59038

프로그래머스

SELECT MIN(DATETIME) AS '시간'
FROM ANIMAL_INS

 

고양이와 개는 몇 마리 있을까

https://school.programmers.co.kr/learn/courses/30/lessons/59040

프로그래머스

SELECT ANIMAL_TYPE, COUNT(ANIMAL_TYPE) AS 'count'
FROM ANIMAL_INS
GROUP BY ANIMAL_TYPE
ORDER BY ANIMAL_TYPE ASC

 

동명 동물 수 찾기

https://school.programmers.co.kr/learn/courses/30/lessons/59041

프로그래머스

SELECT NAME, COUNT(NAME) AS 'COUNT'
FROM ANIMAL_INS
GROUP BY NAME
HAVING COUNT(NAME) > 1
ORDER BY NAME

 

루시와 엘라 찾기

https://school.programmers.co.kr/learn/courses/30/lessons/59046

프로그래머스

SELECT ANIMAL_ID, 
       NAME, 
       SEX_UPON_INTAKE
FROM   ANIMAL_INS
WHERE  NAME IN('Lucy', 'Ella', 'Pickle', 'Rogan', 'Sabrina', 'Mitty')

 

이름에 el이 들어가는 동물 찾기

https://school.programmers.co.kr/learn/courses/30/lessons/59047

프로그래머스

SELECT ANIMAL_ID,
       NAME
FROM   ANIMAL_INS
WHERE  NAME LIKE '%EL%' AND ANIMAL_TYPE = 'Dog'
ORDER BY NAME ASC

 

동물 수 구하기

https://school.programmers.co.kr/learn/courses/30/lessons/59406

프로그래머스

SELECT COUNT(*) AS 'count'
FROM ANIMAL_INS

 

중복 제거하기

https://school.programmers.co.kr/learn/courses/30/lessons/59408

프로그래머스

SELECT COUNT(DISTINCT NAME) AS 'count'
FROM ANIMAL_INS

 

중성화 여부 파악하기

https://school.programmers.co.kr/learn/courses/30/lessons/59409

프로그래머스

SELECT ANIMAL_ID,
       NAME,
       CASE WHEN SEX_UPON_INTAKE LIKE '%Neutered%' 
       OR SEX_UPON_INTAKE LIKE '%Spayed%' THEN 'O'
       ELSE 'X' END AS '중성화'
FROM   ANIMAL_INS
ORDER
BY     ANIMAL_ID ASC

 

NULL 처리하기

https://school.programmers.co.kr/learn/courses/30/lessons/59410

프로그래머스

SELECT ANIMAL_TYPE,
       CASE WHEN NAME IS NULL THEN 'No name' ELSE NAME END AS NAME,
       SEX_UPON_INTAKE
FROM   ANIMAL_INS
ORDER
BY     ANIMAL_ID ASC

 

입양 시각 구하기(1)

https://school.programmers.co.kr/learn/courses/30/lessons/59412

프로그래머스

SELECT HOUR(DATETIME) AS 'HOUR', COUNT(DATETIME) AS 'COUNT'
FROM ANIMAL_OUTS
GROUP BY HOUR(DATETIME)
HAVING HOUR >= 9 and HOUR <= 19
ORDER BY HOUR(DATETIME) ASC