Completed Sql4

FriendRequestsII.sql

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+'''
+4 Problem 4 : Friend Requests II (https://leetcode.com/problems/friend-requests-ii-who-has-the-most-friends/ )
+'''
+
+WITH CTE AS (
+    SELECT requester_id AS id
+    FROM RequestAccepted
+    UNION ALL
+    SELECT accepter_id AS id
+    FROM RequestAccepted )
+
+SELECT id, COUNT(id) AS num
+FROM CTE
+GROUP BY id
+ORDER BY num DESC  
+LIMIT 1

LeagueStatistics.sql

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+'''
+2 Problem 2 : League Statistics (https://leetcode.com/problems/league-statistics/ )
+'''
+
+WITH CTE AS (
+    SELECT home_team_id AS r1, away_team_id AS r2, home_team_goals AS g1, away_team_goals AS g2 FROM Matches
+    UNION ALL
+    SELECT away_team_id AS r1, home_team_id AS r2, away_team_goals AS g1, home_team_goals AS g2 FROM Matches )
+
+SELECT t.team_name, COUNT(c.r1) AS 'matches_played', SUM(
+    CASE 
+        WHEN c.g1 > c.g2 THEN 3
+        WHEN c.g1 = c.g2 THEN 1
+        ELSE 0
+    END    
+) AS 'points', SUM(c.g1) AS 'goal_for', SUM(c.g2) AS 'goal_against', SUM(c.g1) - SUM(c.g2) AS 'goal_diff'
+FROM Teams t JOIN CTE c ON t.team_id = c.r1 GROUP BY c.r1 ORDER BY points DESC, goal_diff DESC, t.team_name

SalesPerson.sql

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+'''
+3 Problem 3 : Sales Person (https://leetcode.com/problems/sales-person/ )
+'''
+
+SELECT name
+FROM SalesPerson
+WHERE sales_id NOT IN (
+    SELECT sales_id
+    FROM Orders
+    JOIN Company ON Company.com_id = Orders.com_id
+    WHERE name = 'RED'
+)

TheNumberOfSeniorsAndJuniorsToJoinTheCompany.sql

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+'''
+Sql4
+
+1 Problem 1 : The Number of Seniors and Juniors to Join the Company (https://leetcode.com/problems/the-number-of-seniors-and-juniors-to-join-the-company/)
+'''
+
+WITH CTE AS (SELECT employee_id, experience, salary, 
+SUM(salary) OVER (PARTITION BY experience ORDER BY salary, employee_id)
+AS 'rsum' FROM Candidates)
+
+SELECT 'Senior' AS experience, COUNT(employee_id) AS accepted_candidates
+FROM CTE
+WHERE experience = 'Senior' AND rsum <= 70000
+UNION 
+SELECT 'Junior' AS experience, COUNT(employee_id) AS accepted_candidates
+FROM CTE
+WHERE experience = 'Junior' AND rsum <= (SELECT 70000 - IFNULL(MAX(rsum), 0) FROM CTE WHERE experience = 'Senior' AND rsum <= 70000)
+