Find Second Highest Salary in SQL

In real-world scenarios, you'll often need to query for the nth highest salary. Let's see how to find the second-highest salary in SQL.

Example

Consider a sample table named Company with columns Employee and Salary:

Table Name: Company

Method 1: Using a Subquery

In this method, the inner subquery finds the highest salary from the Employee table. The outer query then finds the highest salary by excluding the actual highest salary from the table.

Example

SELECT MAX(Salary)
FROM Employee
WHERE Salary NOT IN (SELECT MAX(Salary) FROM Employee);

Method 2: Using the LIMIT Clause

Here, the query selects all distinct salary values from the Employee table, orders them in descending order, and then selects the second record using the LIMIT clause.

Example

SELECT DISTINCT Salary
FROM Employee 
ORDER BY Salary DESC LIMIT 1,1;

Note: This method uses the LIMIT keyword, which may not be supported by all database systems. Currently, it's supported in MySQL and PostgreSQL.

Method 3: Using NOT EXISTS

In the outer query, we select the salary from the employees table and alias it as e1.

The inner query also uses the employees table and aliases it as e2. This query checks if there exists a salary in the employees table that is greater than the current salary in the outer query. The NOT EXISTS clause checks if the inner query returns any rows. If the inner query returns no rows, it means there is no salary greater than the current salary in the outer query. In this case, the current salary is the second-highest salary.

Example

SELECT Salary
FROM Employee e1
WHERE NOT EXISTS 
    (SELECT 1
     FROM Employee e2
     WHERE e2.salary > e1.salary);

Method 4: Using the Window Function

Here, a rank will be assigned to each salary in descending order. The second-highest salary will have a rank of 2.

Example

SELECT Salary
FROM 
    (SELECT Salary, DENSE_RANK() OVER (ORDER BY Salary DESC) AS rk
     FROM Employee) AS RE
WHERE rk = 2;