From 1c22a65199502352b2815a14bab920b6c436a6cd Mon Sep 17 00:00:00 2001
From: Aniruddh <amalankia@mail.sfsu.edu>
Date: Sun, 8 Jun 2025 18:52:51 -0700
Subject: [PATCH] Done SQL2

---
 DepartmentTopThreeSalaries.sql | 16 ++++++++++++++++
 ExchangeSeat.sql               |  2 ++
 RankScore.sql                  |  3 +++
 TreeNode.sql                   |  4 ++++
 4 files changed, 25 insertions(+)
 create mode 100644 DepartmentTopThreeSalaries.sql
 create mode 100644 ExchangeSeat.sql
 create mode 100644 RankScore.sql
 create mode 100644 TreeNode.sql

diff --git a/DepartmentTopThreeSalaries.sql b/DepartmentTopThreeSalaries.sql
new file mode 100644
index 0000000..3128f8b
--- /dev/null
+++ b/DepartmentTopThreeSalaries.sql
@@ -0,0 +1,16 @@
+WITH ranks AS (
+  SELECT
+    d.name AS department,
+    e.name AS employee,
+    e.salary,
+    DENSE_RANK() OVER(PARTITION BY d.id ORDER BY e.salary DESC) AS salary_rank
+  FROM employee e
+  JOIN department d
+    ON d.id = e.departmentId
+)
+SELECT
+  department,
+  employee,
+  salary
+FROM ranks
+WHERE salary_rank <= 3;
diff --git a/ExchangeSeat.sql b/ExchangeSeat.sql
new file mode 100644
index 0000000..3b38885
--- /dev/null
+++ b/ExchangeSeat.sql
@@ -0,0 +1,2 @@
+SELECT s1.id, COALESCE(s2.student , s1.student) AS 'student' FROM seat s1 LEFT JOIN seat s2 
+ON (s1.id +1) ^ 1 - 1 = s2.id ORDER BY s1.id;
\ No newline at end of file
diff --git a/RankScore.sql b/RankScore.sql
new file mode 100644
index 0000000..97c0dd3
--- /dev/null
+++ b/RankScore.sql
@@ -0,0 +1,3 @@
+# Write your MySQL query statement below
+SELECT s1.score , (SELECT COUNT(DISTINCT s2.score) from scores s2 where s2.score >= s1.score) AS 'rank' 
+    FROM SCORES s1 ORDER BY s1.score DESC;
\ No newline at end of file
diff --git a/TreeNode.sql b/TreeNode.sql
new file mode 100644
index 0000000..5ce50f9
--- /dev/null
+++ b/TreeNode.sql
@@ -0,0 +1,4 @@
+SELECT id , IF(
+    ISNULL(p_id) , 'Root' , IF(id IN (SELECT DISTINCT p_id from tree) , 'Inner' , 'Leaf')
+        
+) AS 'type' from tree;
\ No newline at end of file