내배캠 기록장

SQL 코드카타Q133. Weather Observation Station 11. 문제 링크: https://www.hackerrank.com/challenges/weather-observation-station-1/problem2. 정답 코드:SELECT CITY, STATEFROM STATION; Q146. Employee Names1. 문제 링크: https://www.hackerrank.com/challenges/name-of-employees/problem2. 정답 코드:SELECT nameFROM EmployeeORDER BY name; Q147. Employee Salaries1. 문제 링크: https://www.hackerrank.com/challenges/salary-of-..

+ pandas에서는 .copy()가 deepcopy임Q4. 아래 코드의 출력 결과로 올바른 것은? 🚀 도전nums = [3,1,2]result = nums.sort()print(nums)print(result)A. [1, 2, 3] / [1, 2, 3]B. [3, 1, 2] / NoneC. [1, 2, 3] / NoneD. 오류 발생(sort()는 반환값이 반드시 리스트여야 함)-> sort는 원본 자체를 바꿔주는 메서드이기 때문에 result는 반환되지 않음반면 sorted는 원본을 바꾸지 않고 새로운 반환값을 줌Q6. 더 큰 수 반환 함수 🧰 필수두 수 a, b를 받아 더 큰 값을 반환하는 함수 bigger(a, b)를 작성하세요.(두 수가 같다면 어떤 수가 나와도 됨.)예: bigger(3, ..

SQL 코드카타Q130. Select By ID1. 문제 링크: https://www.hackerrank.com/challenges/select-by-id/problem2. 정답 코드:SELECT *FROM CITYWHERE ID = "1661"; Q131. Japanese Cities' Attributes1. 문제 링크: https://www.hackerrank.com/challenges/japanese-cities-attributes/problem2. 정답 코드:SELECT *FROM CITYWHERE COUNTRYCODE = "JPN"; Q132. Japanese Cities' Names 1. 문제 링크: https://www.hackerrank.com/challenges/japanese-citie..

SQL 코드카타Q127. Revising the Select Query I1. 문제 링크: https://www.hackerrank.com/challenges/revising-the-select-query/problem2. 정답 코드:SELECT *FROM CITYWHERE population > 100000 AND CountryCode = "USA"; Q128. Revising the Select Query II1. 문제 링크: https://www.hackerrank.com/challenges/revising-the-select-query-2/problem2. 정답 코드:SELECT NAMEFROM CITYWHERE population > 120000 AND CountryCode = "USA"; ..

SQL 코드카타Q125. 1327. List the Products Ordered in a Period1. 문제 링크: https://leetcode.com/problems/list-the-products-ordered-in-a-period/description/2. 정답 코드:SELECT p.product_name, SUM(o.unit) as unitFROM Orders as oJOIN Products as p ON p.product_id = o.product_idWHERE SUBSTR(o.order_date, 1, 7) = '2020-02'GROUP BY p.product_nameHAVING SUM(o.unit) >= 100 Q92. 1251. Average Selling Price1. ..

SQL 코드카타Q99. 2356. Number of Unique Subjects Taught by Each Teacher1. 문제 링크: https://leetcode.com/problems/number-of-unique-subjects-taught-by-each-teacher/description/2. 정답 코드:SELECT teacher_id, COUNT(DISTINCT subject_id) as cntFROM TeacherGROUP BY teacher_id; Q100. 1141. User Activity for the Past 30 Days I1. 문제 링크: https://leetcode.com/problems/user-activity-for-the-past-30-days-i/2. 정답..

SQL 코드카타Q94. 1633. Percentage of Users Attended a Contest1. 문제 링크: https://leetcode.com/problems/percentage-of-users-attended-a-contest/description/2. 정답 코드:SELECT r.contest_id, ROUND(COUNT(u.user_id)/(SELECT COUNT(*) FROM Users)*100, 2) as percentageFROM Users as uJOIN Register as r ON u.user_id = r.user_idGROUP BY r.contest_idORDER BY percentage DESC, r.contest_id ASC;3. 오류 상황: 전체 비율이 1..

SQL 코드카타Q87. 577. Employee Bonus1. 문제 링크: https://leetcode.com/problems/employee-bonus/description/2. 정답 코드:SELECT e.name, b.bonusFROM Employee as eLEFT JOIN Bonus as b ON e.empId = b.empIdWHERE b.bonus Q88. 1280. Students and Examinations ★어려움★1. 문제 링크: https://leetcode.com/problems/students-and-examinations/description/2. 정답 코드:SELECT s.student_id, s.student_name, sb.subject_..

SQL 코드카타Q82. 1378. Replace Employee ID With The Unique Identifier1. 문제 링크: https://leetcode.com/problems/replace-employee-id-with-the-unique-identifier/description/2. 정답 코드:SELECT u.unique_id, e.nameFROM Employees as eLEFT JOIN EmployeeUNI as u ON e.id = u.idORDER BY u.unique_id Q83. 1068. Product Sales Analysis I1. 문제 링크: https://leetcode.com/problems/product-sales-analysis-i/2. 정답 코드:SE..

SQL 코드카타Q79. 595. Big Countries1. 문제 링크: https://leetcode.com/problems/big-countries/description/2. 정답 코드:SELECT name, population, areaFROM WorldWHERE area >= 3000000 or population >= 25000000ORDER BY name; Q80. 1148. Article Views I1. 문제 링크: https://leetcode.com/problems/article-views-i/description/2. 정답 코드:SELECT DISTINCT author_id as idFROM ViewsWHERE author_id = viewer_idORDER BY au..