Studying data

You did such a great job helping Julia with her last coding contest challenge that she wants you to work on this one, too! The total score of a hacker is the sum of their maximum scores for all of the challenges. Write a query to print the hacker_id, name, and total score of the hackers ordered by the descending score. If more than one hacker achieved the same total score, then sort the result b..

Julia asked her students to create some coding challenges. Write a query to print the hacker_id, name, and the total number of challenges created by each student. Sort your results by the total number of challenges in descending order. If more than one student created the same number of challenges, then sort the result by hacker_id. If more than one student created the same number of challenges ..

Harry Potter and his friends are at Ollivander's with Ron, finally replacing Charlie's old broken wand. Hermione decides the best way to choose is by determining the minimum number of gold galleons needed to buy each non-evil wand of high power and age. Write a query to print the id, age, coins_needed, and power of the wands that Ron's interested in, sorted in order of descending power. If more ..

Julia just finished conducting a coding contest, and she needs your help assembling the leaderboard! Write a query to print the respective hacker_id and name of hackers who achieved full scores for more than one challenge. Order your output in descending order by the total number of challenges in which the hacker earned a full score. If more than one hacker received full scores in same number of..

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 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. ..

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.CountryCode and COUNTRY.Code are matching key columns. Input Format The CITY and COUNTRY tables are described as follows: [MySQL Solution] SELECT COUNTRY.CONTINENT, FLOOR(AVG(CITY.POPULATION)) ..

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. Input Format The CITY and COUNTRY tables are described as follows: [MySQL Solution 1] SELECT SUM(CITY.POPULATION) FROM CITY, COUNTRY WHERE CITY.COUNTRYCODE = COUNTRY.CODE AND COUNTRY.CONTINENT = 'Asia'; [MySQL Solution ..

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 decimal places. Input Format The STATION table is described as follows: where LAT_N is the northern latitude and LONG_W is the western longitude. [MySQL Solution 1] SELECT ROUND(AVG(S.LAT_N), 4) FROM STATION S WHERE..