completed sql 4

1st problem.sql

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+# Write your MySQL query statement below
+
+with seniors as 
+(
+select employee_id,
+70000 - rolling_sum as budget_left
+from
+(select *,
+sum(salary) over(order by salary asc) as rolling_sum
+from Candidates
+where experience = 'Senior') a
+where rolling_sum <= 70000
+),
+
+juniors as 
+(
+select a.employee_id
+from
+(select *,
+sum(salary) over(order by salary asc) as rolling_sum
+from Candidates
+where experience = 'Junior') a
+where rolling_sum <= (select coalesce(min(budget_left), 70000) from seniors)
+)
+
+select 'Senior' as experience,
+coalesce(count(employee_id), 0) as accepted_candidates
+from seniors
+union all
+select 'Junior' as experience,
+coalesce(count(employee_id), 0) as accepted_candidates
+from juniors

2nd problem.sql

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+select
+    team_name, count(*) as matches_played, sum(case when home > away then 3 when home = away then 1 else 0 end) as points, sum(home) as goal_for
+    , sum(away) as goal_against, sum(home) - sum(away) as goal_diff
+
+from 
+    (select home_team_id, home_team_goals as home, away_team_goals as away from matches
+     union all
+     select away_team_id as home_team_id, away_team_goals as home, home_team_goals as away from matches
+	 ) g
+join teams t on g.home_team_id = t.team_id
+group by 1
+order by 3 desc, 6 desc, 1

3rd problem.sql

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+select salesperson.name
+from orders o join company c on (o.com_id = c.com_id and c.name = 'RED')
+right join salesperson on salesperson.sales_id = o.sales_id
+where o.sales_id is null

4th problem.sql

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+WITH all_ids AS (
+    SELECT ra.requester_id AS id, COUNT(*) AS cnt
+    FROM RequestAccepted ra
+    GROUP BY ra.requester_id
+
+    UNION ALL 
+
+    SELECT ra.accepter_id AS id, COUNT(*) AS cnt 
+    FROM RequestAccepted ra
+    GROUP BY ra.accepter_id
+)
+
+SELECT id, SUM(cnt) AS num
+FROM all_ids
+GROUP BY id
+ORDER BY num DESC
+LIMIT 1