Data Analyst KIM

LeetCode - The World's Leading Online Programming Learning Platform Level up your coding skills and quickly land a job. This is the best place to expand your knowledge and get prepared for your next interview. leetcode.com 이 문제는 DENSE_RANK를 사용하면 되는 간단한 문제였음 + AS 이후 'Rank'처럼 따옴표를 사용해주는 것이 포인트 SELECT Score , DENSE_RANK() OVER (ORDER BY Score DESC) AS 'Rank' FROM Scores

1. 문제 설명 2. 문제 3. 예시 3. 내 코드 - SUM(Weight) OVER(ORDER BY Turn)을 통해서 누적 합 계산 - 조건절과 LIMIT를 이용하여 1개의 값을 출력 WITH t AS ( SELECT Turn , person_id , person_name , Weight , SUM(Weight) OVER(ORDER BY Turn) AS total FROM Queue ORDER BY Turn desc ) SELECT person_name FROM t WHERE total

문제 풀이 1. 부모 노드가 없는 경우 => Root 2. 부모노드가 있고, 자신이 부모노드인 경우 => Inner 3. 나머지 => Leaf SELECT id , (CASE WHEN p_id IS NULL THEN 'Root' WHEN id IN (SELECT p_id FROM Tree) THEN 'Inner' ELSE 'Leaf' END) AS 'type' FROM Tree ORDER BY id

설명 문제 예시 Buy이면 -price , Sell이면 price를 집계 SELECT stock_name , SUM(CASE WHEN operation = 'Buy' THEN -price ELSE price END) AS capital_gain_loss FROM Stocks GROUP BY stock_name

WITH tab AS ( SELECT car.daily_fee , car.car_type , his.history_id , DATEDIFF(END_DATE, START_DATE) + 1 AS period , CASE WHEN DATEDIFF(END_DATE, START_DATE) + 1 >= 90 THEN '90일 이상' WHEN DATEDIFF(END_DATE, START_DATE) + 1 >= 30 THEN '30일 이상' WHEN DATEDIFF(END_DATE, START_DATE) + 1 >= 7 THEN '7일 이상' ELSE 'NONE' END AS duration_type FROM CAR_RENTAL_COMPANY_RENTAL_HISTORY AS his INNER JOIN CAR_RENTA..

SELECT DATE_FORMAT(SALES_DATE,"%Y-%m-%d") SALES_DATE , PRODUCT_ID , USER_ID , SALES_AMOUNT FROM ONLINE_SALE WHERE SALES_DATE >= '2022-03-01' and SALES_DATE = '2022-03-01' and SALES_DATE < '2022-04-01' ORDER BY SALES_DATE , PRODUCT_ID , USER_ID