문제 https://www.hackerrank.com/challenges/weather-observation-station-4/problem?isFullScreen=true Weather Observation Station 4 | HackerRank Find the number of duplicate CITY names in STATION. www.hackerrank.com 풀이(MSSQL) SELECT COUNT(CITY) - COUNT(DISTINCT CITY) FROM STATION 처음에는 문제에 대한 이해가 되지 않아서 생각을 깊게 해야했던 것 같지만 총 CITY 수에서 중복되지 않은 CITY의 개수를 빼면 해결되는 문제였다.

문제 https://www.hackerrank.com/challenges/weather-observation-station-3/problem?isFullScreen=true Weather Observation Station 3 | HackerRank Query a list of unique CITY names with even ID numbers. www.hackerrank.com 풀이(MSSQL) SELECT DISTINCT A.CITY FROM STATION AS A WHERE (A.ID % 2) = 0 문제에서 중요한 조건은 ID가 짝수, 중복을 제외한 도시 이름을 출렸했어야 한다.

문제 https://www.hackerrank.com/challenges/weather-observation-station-1/problem?isFullScreen=true Weather Observation Station 1 | HackerRank Write a query to print the CITY and STATE for each attribute in the STATION table. www.hackerrank.com 풀이(MSSQL) SELECT CITY, STATE FROM STATION

문제 https://www.hackerrank.com/challenges/japanese-cities-name/problem?isFullScreen=true Japanese Cities' Names | HackerRank In this challenge, you will query a list of all the Japanese cities' names. www.hackerrank.com 풀이(MSSQL) SELECT NAME FROM CITY WHERE COUNTRYCODE LIKE 'JPN'

문제 https://www.hackerrank.com/challenges/japanese-cities-name/problem?isFullScreen=true Japanese Cities' Names | HackerRank In this challenge, you will query a list of all the Japanese cities' names. www.hackerrank.com 풀이(MSSSQL) SELECT NAME FROM CITY WHERE COUNTRYCODE LIKE 'JPN'

문제 https://www.hackerrank.com/challenges/japanese-cities-attributes/problem?isFullScreen=true Japanese Cities' Attributes | HackerRank Query the attributes of all the cities in Japan. www.hackerrank.com 풀이(MSSQL) SELECT * FROM CITY WHERE COUNTRYCODE LIKE 'JPN'

문제 https://www.hackerrank.com/challenges/select-by-id/problem?isFullScreen=true Select By ID | HackerRank Query the details of the city with ID 1661. www.hackerrank.com 풀이(MSSQL) SELECT * FROM CITY WHERE ID = 1661

문제 https://www.hackerrank.com/challenges/select-all-sql/problem?isFullScreen=true Select All | HackerRank Query all columns for every row in a table. www.hackerrank.com 풀이(MSSQL) SELECT * FROM CITY