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HackerRank - SQL (Intermediate) Certificate HackerRank라는 사이트가 있다. SQL 코테 문제도 풀어볼 수 있고, Basic / Intermediate / Advanced 레벨 별 시험을 쳐서 자격도 딸 수 있는 모양이다. 아 물론 SQL 말고 다른 언어도 많다. https://www.hackerrank.com/ HackerRank - Online Coding Tests and Technical Interviews HackerRank is the market-leading coding test and interview solution for hiring developers. Start hiring at the pace of innovation! www.hackerrank.com 코딩테스트 문제는 아직 Leetcode나 프로그래머스, 그리고 ..
178. Rank Scores Table: Scores +-------------+---------+ | Column Name | Type | +-------------+---------+ | id | int | | score | decimal | +-------------+---------+ id is the primary key (column with unique values) for this table. Each row of this table contains the score of a game. Score is a floating point value with two decimal places. Write a solution to find the rank of the scores. The ranking should be cal..
185. Department Top Three Salaries Table: Employee +--------------+---------+ | Column Name | Type | +--------------+---------+ | id | int | | name | varchar | | salary | int | | departmentId | int | +--------------+---------+ id is the primary key (column with unique values) for this table. departmentId is a foreign key (reference column) of the ID from the Department table. Each row of this table indicates the ID, name, and sal..
184. Department Highest Salary Table: Employee +--------------+---------+ | Column Name | Type | +--------------+---------+ | id | int | | name | varchar | | salary | int | | departmentId | int | +--------------+---------+ id is the primary key (column with unique values) for this table. departmentId is a foreign key (reference columns) of the ID from the Department table. Each row of this table indicates the ID, name, and sa..
SQL 고득점 kit(GROUP BY) - 저자 별 카테고리 별 매출액 집계하기 -- 풀이 -- '2022년 1월', '저자 별 카테고리 별 매출액', '저자 ID 오름차순, 카테고리 내림차순' SELECT B.AUTHOR_ID , A.AUTHOR_NAME , B.CATEGORY , SUM(B.PRICE*BS.SALES) AS TOTAL_SALES FROM BOOK_SALES BS LEFT JOIN BOOK B ON BS.BOOK_ID = B.BOOK_ID LEFT JOIN AUTHOR A ON B.AUTHOR_ID = A.AUTHOR_ID WHERE YEAR(BS.SALES_DATE) = '2022' AND MONTH(BS.SALES_DATE) = '1' GROUP BY A.AUTHOR_NAME, B.CATEGORY ORDER BY A.AUTHOR_ID, B.CATEGORY DES..
[Github] New Repository 만들기 아래 블로그 글을 많이 참고했다. https://angelplayer.tistory.com/222 [Github] Github 저장소(Repository) 생성 & 초기 설정 Repository(저장소) 생성하기 github에 접속하여, Repositories 탭으로 이동하면 [New] 버튼이 있습니다. New 버튼을 누르면 새로운 Repositoy를 생성하는 화면이 나옵니다. 여기서 Repository Name을 설정 한 후 [Cr angelplayer.tistory.com 깃헙 계정이 없으면 계정부터 만들어야 하는데, 나는 이미 계정이 있으니 패스! 1. Repositories에 들어가보자. 2. 그럼 아래와 같이 우측에 New 버튼이 있다. 딱 봐도 이걸 눌러줘야 할 것 같다. 3. 이것저것 입력하..
[Mode] Investigating a Drop in User Engagement(2) Mode에서 제공하는 SQL Analytics Training 실습하기. (1)에 이어서... [Data Analysis] - [Mode] Investigating a Drop in User Engagement(1) [Mode] Investigating a Drop in User Engagement(1) Mode에서 제공하는 SQL Analytics Training 실습하기. https://mode.com/sql-tutorial/a-drop-in-user-engagement Investigating a Drop in User Engagement | SQL Analytics Training - Mode In this lesson we'll cover: Before starting, be sure to re..
[Mode] Investigating a Drop in User Engagement(1) Mode에서 제공하는 SQL Analytics Training 실습하기. https://mode.com/sql-tutorial/a-drop-in-user-engagement Investigating a Drop in User Engagement | SQL Analytics Training - Mode In this lesson we'll cover: Before starting, be sure to read the overview to learn a bit about Yammer as a company. Yammer's Analysts are responsible for triaging product and business problems as they come up. In many cases, thes..