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[hackerrank] Prepare > SQL > Aggregation > Top Earners [문제] We define an employee's total earnings to be their monthly worked, and the maximum total earnings to be the maximum total earnings for any employee in the Employee table. Write a query to find the maximum total earnings for all employees as well as the total number of employees who have maximum total earnings. Then print these values as..

[hackerrank] Prepare > SQL > Aggregation > The Blunder [문제] Samantha was tasked with calculating the average monthly salaries for all employees in the EMPLOYEES table, but did not realize her keyboard's key was broken until after completing the calculation. She wants your help finding the difference between her miscalculation (using salaries with any zeros removed), and the actual average salary..

[hackerrank] Prepare > SQL > Aggregation > Population Density Difference [문제] Query the difference between the maximum and minimum populations in CITY. Input Format The CITY table is described as follows: [MYSQL] [ORCALE] select max(population)-min(population) from city;

[hackerrank] Prepare > SQL > Aggregation > Japan Population [문제] Query the sum of the populations for all Japanese cities in CITY. The COUNTRYCODE for Japan is JPN. Input Format The CITY table is described as follows: [MYSQL] [ORCALE] select sum(population) from city where countrycode = 'JPN';

[hackerrank] Prepare > SQL > Aggregation > Average Population [문제] Query the average population for all cities in CITY, rounded down to the nearest integer. Input Format The CITY table is described as follows: [MYSQL] [ORCALE] select round(avg(population),0) from city;

[hackerrank] Prepare > SQL > Aggregation > Revising Aggregations - Averages [문제] Query the average population of all cities in CITY where District is California. Input Format The CITY table is described as follows: [MYSQL] [ORCALE] select avg(population) from city where district = 'California';

[hackerrank] Prepare > SQL > Aggregation > > Revising Aggregations - The Sum Function [문제] Query the total population of all cities in CITY where District is California. Input Format The CITY table is described as follows: [MYSQL] [ORCALE] select sum(population) from city where district = 'California';

[hackerrank] Prepare > SQL > Aggregation > Weather Observation Station 20 [문제] 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 l..

[hackerrank] Prepare > SQL > Aggregation > Revising Aggregations - The Count Function [문제] Query a count of the number of cities in CITY having a Population larger than . Input Format The CITY table is described as follows: [MYSQL] [ORCALE] select count(*) from city where population > 100000;

[hackerrank] Prepare > SQL > Advanced Select > New Companies [문제] Amber's conglomerate corporation just acquired some new companies. Each of the companies follows this hierarchy: Given the table schemas below, write a query to print the company_code, founder name, total number of lead managers, total number of senior managers, total number of managers, and total number of employees. Order your o..