SQL

SQL Project Planning | HackerRank Write a query to output the start and end dates of projects listed by the number of days it took to complete the project in ascending order. www.hackerrank.com Problem If the End_Date of the tasks are consecutive, then they are part of the same project. Samantha is interested in finding the total number of different projects completed. Write a query to output th..

The Report | HackerRank Write a query to generate a report containing three columns: Name, Grade and Mark. www.hackerrank.com Problem Ketty gives Eve a task to generate a report containing three columns: Name, Grade and Mark. Ketty doesn't want the NAMES of those students who received a grade lower than 8. The report must be in descending order by grade -- i.e. higher grades are entered first. I..

Average Population of Each Continent | HackerRank Query the names of all continents and their respective city populations, rounded down to the nearest integer. www.hackerrank.com Problem Given the CITY and COUNTRY tables, query the names of all the continents (COUNTRY.Continent) and their respective average city populations (CITY.Population) rounded down to the nearest integer. Note: CITY.Countr..

African Cities | HackerRank Query the names of all cities on the continent 'Africa'. www.hackerrank.com Problem 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. -> 아프리카 대륙에 있는 모든 도시의 이름을 출력하시오. Answer select a.name from city a inner join country b on a.countrycode = b.code where b.c..

Weather Observation Station 20 | HackerRank Query the median of Northern Latitudes in STATION and round to 4 decimal places. www.hackerrank.com Problem A median is defined as a number separating the higher half of a data set from the lower half. Query the median of the Northern Latitudes (LAT_N) from STATION and round your answer to 4 decimal places. -> lat_n의 중간 값을 반올림 해서 소수점 4번째 자리까지 출력하시오. SQ..

Weather Observation Station 19 | HackerRank Query the Euclidean Distance between two points and round to 4 decimal digits. www.hackerrank.com Problem Consider P1(a,b) and P2(c,d) to be two points on a 2D plane where (a,b) are the respective minimum and maximum values of Northern Latitude (LAT_N) and (c,d) are the respective minimum and maximum values of Western Longitude (LONG_W) in STATION. Que..

Weather Observation Station 18 | HackerRank Query the Manhattan Distance between two points, round or truncate to 4 decimal digits. www.hackerrank.com Problem Consider P1(a,b) and P2(c,d) to be two points on a 2D plane. a happens to equal the minimum value in Northern Latitude (LAT_N in STATION). b happens to equal the minimum value in Western Longitude (LONG_W in STATION). c happens to equal th..

Weather Observation Station 17 | HackerRank Query the Western Longitude for the smallest value of the Northern Latitudes greater than 38.7780 in STATION and round to 4 decimal places. www.hackerrank.com Problem Query the Western Longitude (LONG_W)where the smallest Northern Latitude (LAT_N) in STATION is greater than 38.7780 . Round your answer to 4 decimal places. -> lat_n 이 38.7780보다 큰 lat_n중에..