[내일배움캠프] 2023-01-11 TIL

선발대 - SQL 쿼리문 테스트

문제점

한동안 sequelize를 이용해서만 db에 요청하다 보니 기본적인 sql 쿼리문에 대한 지식이 부족함을 느꼈다.

알게 된 점

4문제를 통해서  SELECT문의 다양한 활용을 익혔다. LIKE, CASE, GROUP BY, HAVING, ORDER BY 등을 잘 기억하자.

 

A. SELECT * FROM employees WHERE (salary ≤ 50000000 and department_id = 17) OR department_id = 5 OR comm > 0

 

A2. SELECT student_name FROM students WHERE (track IN (’Node.js’, ‘React’) AND (student_name LIKE ‘김%’ OR

 

A3. SELECT name, CASE WHEN rank_score ≤ 1000 THEN ‘IRON’ WHEN rank_score ≤ 2000 THEN ‘BRONZE’ WHEN rank_score ≤ 3000 THEN ‘SILVER’ ELSE ‘GOD’ END AS rank_result FROM lol_players student_name LIKE ‘%호’))

 

A4. SELECT ID, NAME, HOST_ID FROM PLACES WHERE HOST_ID IN (SELECT HOST_ID FROM PLACES GROUP BY HOST_ID HAVING COUNT(HOST_ID) > 1) ORDER BY ID