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 | ---------------------
link:{sourcedir}/_0176_SecondHighestSalary.sql[role=include]