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select max(case when occupation = 'Doctor' then name end) as Doctor, max(case when occupation = 'Professor' then name end) as Professor, max(case when occupation = 'Singer' then name end) as Singer, max(case when occupation = 'Actor' then name end) as Actorfrom (select name, occupation, row_number() over(partition by occupation order by name as..

select case when grade >= 8 then name else "NULL" end as name, grade, marksfrom students as sjoin grades as g on s.marks between g.min_mark and g.max_markorder by grade desc, name asc, marks asc

select h.hacker_id, h.name, sum(b.score) as sum_scorefrom hackers as hjoin (select hacker_id, challenge_id, max(score) as scorefrom submissionsgroup by hacker_id, challenge_id ) as b on h.hacker_id = b.hacker_idgroup by 1,2having sum_score > 0order by sum_score desc, hacker_id asc

https://www.hackerrank.com/challenges/challenges/problem Challenges | HackerRankPrint the total number of challenges created by hackers.www.hackerrank.comwith t1 as(select hacker_id, count(distinct challenge_id) as c_cntfrom challengesgroup by hacker_id )select t1.hacker_id, hackers.name, c_cntfrom t1join hackers on t1.hacker_id = hackers.hacker_idwhere 1=1 and (t1.c_cnt = (select max(c_cn..