Tags: "leetcode", "sql", access_time 1-min read

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Second Highest Salary

Created: March 3, 2020 by [lek-tin]

Last updated: April 7, 2020

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                 |
+---------------------+

Solution (naive)

SELECT max(Salary) as SecondHighestSalary
FROM Employee
WHERE Salary
NOT IN (SELECT max(Salary) FROM Employee)

Solution

This solution considers when second highest salary doesn’t exist

SELECT
    IFNULL(
        (
            SELECT
                DISTINCT Salary
            FROM
                Employee
            ORDER BY Salary Desc
            LIMIT 1
            OFFSET 1
        ),
        NULL
    ) AS SecondHighestSalary