Completed Sql2

1.sql

@@ -0,0 +1,8 @@
+# Write your MySQL query statement below
+WITH CTE AS (
+    SELECT score,
+        DENSE_RANK() OVER (ORDER BY score DESC) AS rnk
+    FROM Scores
+)
+SELECT score, rnk AS 'rank'
+FROM CTE

2.sql

@@ -0,0 +1,7 @@
+SELECT (
+    CASE 
+        WHEN id%2 != 0 AND id = cnt THEN id
+        WHEN id%2 != 0 AND id != cnt THEN id+1
+        ELSE id-1
+    END
+) AS 'id', student FROM Seat , (SELECT COUNT(*) AS 'cnt' FROM Seat) AS seat_counts ORDER BY id

3.sql

@@ -0,0 +1,8 @@
+SELECT id, (
+    CASE 
+        WHEN p_id IS NULL THEN 'Root' 
+        WHEN id NOT IN (SELECT DISTINCT p_id FROM Tree WHERE p_id IS NOT NULL) AND p_id IS NOT NULL THEN 'Leaf' 
+        ELSE 'Inner' 
+    END     
+) AS type
+FROM Tree

4.sql

@@ -0,0 +1,11 @@
+WITH CTE AS(
+    SELECT Employee.name, Employee.departmentId, salary, DENSE_RANK() 
+OVER (PARTITION BY Employee.departmentId ORDER BY Employee.salary DESC) AS rnk
+FROM Employee)
+
+
+SELECT Department.name AS Department, CTE.name AS Employee, CTE.salary AS Salary
+FROM CTE
+JOIN Department ON Department.id = CTE.departmentId
+WHERE rnk <= 3
+