select(casewhen grade<8THENNULLELSEname END)name,grade,marksfromstudents,gradeswheremarks between min_Mark andMax_Markorder by grade desc,coalesce(name,marks); 9.Top Competitors image.png image.png 我的错误答案 selectHackers.hacker_id,Hackers.namefromHackersinnerjoinSubmissionson Hackers.hacker_id=S...
在数据去重方面，如New Companies题目，可通过DISTINCT关键字处理重复记录。Weather Observation Station 20的中位数计算则需要先排序和计数，根据奇偶性计算中位数。The Report中的Inequality Join则涉及根据特定范围进行表格合并。Top Competitors部分，通过分段处理，筛选出获得满分的hacker，并按要求排序。在更...
Basic Join African Cities 10 Easy Solution.sql Basic Join Average Population of Each Continent 10 Easy Solution.sql Basic Join The Report 20 Medium Solution.sql Basic Join Top Competitors 30 Medium Solution.sql Basic Join Ollivander's Inventory 30 Medium Solution.sql Basic Join Challenges 30 Mediu...
Top Competitors 我比较喜欢分段写,这样思路更加清晰:首先生成两个子表,一个子表对照每个challenge的满分,一个子表是每个hacker参与的challenge以及它的得分。其次,在主句中把两个子表结合在一起,结合的条件是相同的challenge_id,这样就得到了每个hacker参加的challenge,它的得分,以及该challenge的满分对照表。第三,按照...
47Top CompetitorsSolutionMediumBasic Join 48Ollivander's InventorySolutionMediumBasic Join 49ChallengesSolutionMediumBasic Join 50Contest LeaderboardSolutionMediumBasic Join 51SQL Project PlanningSolutionMediumAdvanced Join 52PlacementsSolutionMediumAdvanced Join ...
See all competitorshackerrank.com Top Traffic Sources The top traffic source to hackerrank.com is Direct traffic, driving 60.29% of desktop visits last month, and Organic Search is the 2nd with 33.96% of traffic. The most underutilized channel is Display. Drill down into the main traffic ...
Basic Join African Cities 10 Easy Solution.sql Basic Join Average Population of Each Continent 10 Easy Solution.sql Basic Join The Report 20 Medium Solution.sql Basic Join Top Competitors 30 Medium Solution.sql Basic Join Ollivander's Inventory 30 Medium Solution.sql Basic Join Challenges 30 Mediu...