Upload 139

Author: ggeerraarrdd

README.md

@@ -171,6 +171,7 @@ The problems and both submitted and site solutions are documented in individual
 | 136   | [Department Top Three Salaries](https://leetcode.com/problems/department-top-three-salaries/description/)                                                     | [Solution](solutions/136_department_top_three_salaries.md)                            | LeetCode    | Hard         |                                                                     |
 | 137   | [Fix Names in a Table](https://leetcode.com/problems/fix-names-in-a-table/description/)                                                                       | [Solution](solutions/137_fix_names_in_a_table.md)                                     | LeetCode    | Easy         | `SUBSTRING()`                                                       |
 | 138   | [Patients With a Condition](https://leetcode.com/problems/patients-with-a-condition/description/)                                                             | [Solution](solutions/138_patients_with_a_condition.md)                                | LeetCode    | Easy         |                                                                     |
+| 139   | [Second Highest Salary](https://leetcode.com/problems/second-highest-salary/description/)                                                                     | [Solution](solutions/139_second_highest_salary.md)                                    | LeetCode    | Medium       |                                                                     |
 <!-- Index End - WARNING: Do not delete or modify this markdown comment. -->
 
 ## Author(s)

solutions/139_second_highest_salary.md

@@ -0,0 +1,52 @@
+# SQL Everyday \#139
+
+## Second Highest Salary
+
+Site: LeetCode\
+Difficulty per Site: Medium
+
+## Problem
+
+Write a solution to find the second highest *distinct* salary from the `Employee` table. If there is no second highest salary, return `null (return None in Pandas)`. [[Full Description](https://leetcode.com/problems/second-highest-salary/description/)]
+
+## Submitted Solution
+
+```sql
+-- Submitted Solution
+WITH cte1 AS (
+    SELECT
+        DISTINCT salary
+    FROM Employee
+),
+cte2 AS (
+    SELECT
+        salary
+        ,ROW_NUMBER() OVER (ORDER BY salary DESC) AS row_num
+        ,COUNT(*) OVER () AS row_count
+    FROM cte1
+)
+SELECT
+    CASE WHEN row_count >= 2 THEN (SELECT salary FROM cte2 WHERE row_num = 2) ELSE null END AS SecondHighestSalary
+FROM cte2
+LIMIT 1
+;
+```
+
+## Site Solution
+
+```sql
+-- LeetCode Solution 
+-- TBD
+```
+
+## Notes
+
+TBD
+
+## NB
+
+
+
+Go to [Index](../?tab=readme-ov-file#index)\
+Go to [Overview](../?tab=readme-ov-file)
+