치킨먹고싶어요

https://www.hackerrank.com/challenges/weather-observation-station-5/problem?isFullScreen=true Weather Observation Station 5 | HackerRank Write a query to print the shortest and longest length city name along with the length of the city names. www.hackerrank.com Answer: SELECT CITY, LENGTH(CITY) FROM STATION ORDER BY LENGTH(CITY), CITY LIMIT 1; SELECT CITY, LENGTH(CITY) FROM STATION ORDER BY LENG..

https://www.hackerrank.com/challenges/the-report/problem?isFullScreen=true The Report | HackerRank Write a query to generate a report containing three columns: Name, Grade and Mark. www.hackerrank.com You are given two tables: Students and Grades. Students contains three columns ID, Name and Marks. Grades contains the following data: Ketty gives Eve a task to generate a report containing three c..

https://www.hackerrank.com/challenges/binary-search-tree-1/problem?isFullScreen=true Binary Tree Nodes | HackerRank Write a query to find the node type of BST ordered by the value of the node. www.hackerrank.com Question: You are given a table, BST, containing two columns: N and P, where N represents the value of a node in Binary Tree, and P is the parent of N. Write a query to find the node typ..

https://www.hackerrank.com/challenges/asian-population/problem?isFullScreen=true Population Census | HackerRank Query the sum of the populations of all cities on the continent 'Asia'. www.hackerrank.com Given the CITY and COUNTRY tables, query the sum of the populations of all cities where the CONTINENT is 'Asia'. Note: CITY.CountryCode and COUNTRY.Code are matching key columns. 해석: 주어진 CITY와 CO..

https://www.hackerrank.com/challenges/african-cities/problem?isFullScreen=true African Cities | HackerRank Query the names of all cities on the continent 'Africa'. www.hackerrank.com Given the CITY and COUNTRY tables, query the names of all cities where the CONTINENT is 'Africa'. Note: CITY.CountryCode and COUNTRY.Code are matching key columns. 해석: 주어진 CITY와 COUNTRY 테이블에서 COUNTINENT가 Africa인 모든 ..

https://leetcode.com/problems/second-highest-salary/ Second Highest Salary - LeetCode 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 문제를 해석 하자면 두 번째로 높은 임금을 구하여라. 그러나 두 번째 높은 값이 없을 경우에는 null을 출력하라라는 뜻입니다. 그러나 문제를 풀 것은 아니고, 이 문제로 WHERE과 SubQuery를 배워봅시다. 일단 아래의 코드가 위에 링크 문제의 답입니다. SELECT MAX..

https://leetcode.com/problems/combine-two-tables/ 해석: Write an SQL query to report the first name, last name, city, and state of each person in the Person table. If the address of a personId is not present in the Address table, report null instead. cs firstName , lastName, city, state를 출력하라, 그러나 Address table에 personId가 없으면, null을 리턴하라는 내용입니다. Person table과 Address table이 나오며 Null이 나오니, 두 테이블을 합..