Solving Second highest salary in SQL. This is also a classic interview question. Please try yourself first to solve the problem and submit your implementation to LeetCode before looking into solution.

Problem Description

Write a SQL query to get the second highest salary from the Employee table.

+----+--------+
| Id | Salary |
+----+--------+
| 1 | 100 |
| 2 | 200 |
| 3 | 300 |
+----+--------+

For example, given the above Employee table, the query should return 200 as the second highest salary. If there is no second highest salary, then the query should return null.

+---------------------+
| SecondHighestSalary |
+---------------------+
| 200 |
+---------------------+

Originally posted at: @github.com/ignacio-chiazzo/Algorithms-Leetcode-Javascript