Completed SQL5

README.md

@@ -1,9 +1,81 @@
 # Sql5
 
 1 Problem 1 : Report Contiguos Dates		(https://leetcode.com/problems/report-contiguous-dates/ )
+Solution:
+
+WITH CTE AS (
+    SELECT  fail_date AS dat,'failed' AS period_state,
+        RANK() OVER (ORDER BY fail_date) AS rnk
+    FROM failed
+    WHERE YEAR(fail_date) = 2019
+
+    UNION ALL
+
+    SELECT  success_date AS dat,'succeeded' AS period_state,
+        RANK() OVER (ORDER BY success_date) AS rnk
+    FROM succeeded
+    WHERE YEAR(success_date) = 2019
+),
+CTE2 AS (
+    SELECT *, RANK() OVER (ORDER BY dat) - rnk AS grp
+    FROM CTE
+)
+SELECT period_state, MIN(dat) AS start_date, MAX(dat) AS end_date
+FROM CTE2
+GROUP BY period_state, grp
+ORDER BY start_date;
+
+
 
 2 Problem 2 : Student Report By Geography		(https://leetcode.com/problems/students-report-by-geography/ )
+Solution:
+
+# Write your MySQL query statement below
+with cte as (Select name as 'America', Row_number() over(order by name) As 'rnk'
+From student 
+where continent = 'America'
+order by America),
+
+cte2 as (Select name as 'Asia', Row_number() over(order by name) As 'rnk'
+From student 
+where continent = 'Asia'
+order by Asia),
+
+ cte3 as (Select name as 'Europe', Row_number() over(order by name) As 'rnk'
+From student 
+where continent = 'Europe'
+order by Europe)
+
+Select America,Asia,Europe 
+from cte2 c2
+right join cte c1
+on c1.rnk = c2.rnk
+left join cte3 c3
+on c1.rnk = c3.rnk
 
 3 Problem 3 : Average Salary Department vs Company		(https://leetcode.com/problems/average-salary-departments-vs-company/description/ )
+Solution:
+
+# Write your MySQL query statement below
+WITH companyAvg as(
+SELECT date_format(pay_date, '%Y-%m') as 'pay_month' , AVG(amount) AS 'CompanyAvg' from salary GROUP BY pay_month
+),
+deptAvg AS(
+SELECT date_format(pay_date, '%Y-%m') as 'pay_month', department_id  , AVG(amount) AS 'departmentAvg' FROM salary join
+employee ON salary.employee_id = employee.employee_id GROUP BY department_id,pay_month
+)
+
+SELECT deptAvg.pay_month , department_id , (
+    CASE
+        WHEN departmentAvg > CompanyAvg THEN 'higher'
+        WHEN departmentAvg < CompanyAvg THEN 'lower'
+        ELSE 'same'
+    END
+) AS 'comparison' FROM companyAvg JOIN deptAvg ON deptAvg.pay_month = companyAvg.pay_month;
 
 4 Problem 4 : Game Play Analysis I		(https://leetcode.com/problems/game-play-analysis-i/ )
+Solution:
+
+Select player_id, min(event_date) as first_login
+from Activity
+group by player_id