For workingHoliday/SQL (2) 썸네일형 리스트형 Hacker Rank Join and aggregation methon I will explain about 2 question about Join and aggregation throuhg hacker rank. first of all, this problem should be used join (or use sub query in where) To summarize question : it should be output the names of all cities where the continent is 'Africa' before checking the answer, please reading the statment. for solving this problem, I mentioned before, we can use join statement or sub query. .. HackerRank SQL To summarize question : just get the max total earning from one table, Employee, and count it how many employees get the hight salary. for soving this problem, I need to conside how can I get the max earnings and how can I count the all of employees who get the most earnings. so, I choose to use aggregation method, SUM and COUNT. It was really easy to get max earnings but for counting the employ.. 이전 1 다음