Find Nth Highest Salary in SQL

In this article, we will write an SQL(Structured Query Language) query to find the N^th highest salary from a database table. We can obtain the 2^nd highest salary, 3^rd highest salary, and so on. Certainly, This is the most commonly asked question in an interview. There are different methods to achieve this, we will understand every technique in detail.

Problem Statement

Assume we have a table named employees with 3 columns namely, EmployeeId, EmployeeName and, EmployeeSalary as shown below ?

EmployeeId	EmployeeName	EmployeeSalary
10001	Mahesh	33000
10002	John	35000
10003	Abdul	34500
10004	Raman	38000

Given task is to find out any N^th order highest salary request like 2^nd highest salary is 35000, 3^rd, and so on.

Data Creation

Let's create the table using the CREATE query ?

CREATE TABLE Employees (
   EmployeeId INT PRIMARY KEY,
   EmployeeName VARCHAR(255),
   EmployeeSalary DECIMAL(10, 2)
);

Now, we will provide the records mentioned above using the INSERT statement

INSERT INTO Employees (EmployeeId, EmployeeName, EmployeeSalary) VALUES
(10001, 'Mahesh', 33000),
(10002, 'John', 35000),
(10003, 'Abdul', 34500),
(10004, 'Raman', 38000);

Find Nth Highest Salary in SQL

We can find the N^th highest salary in SQL

• Using DISTINCT and LIMIT clauses
• Using Correlated Subquery
• Using DENSE_RANK() function

Using DISTINCT and LIMIT clauses

Let's understand the query creation approach

• Find out DISTINCT records of employeeSalary
• Use ORDERBY with descending order to arrange the highest salary on 1^st row
• OFFSET to N-1 skips first N-1 records from sorted result
• Finally, LIMIT 1 to fetch a unique N^th record

Syntax

Following is the query to find the N^th highest salary in SQL where N representing the N^th order of salary ?

SELECT DISTINCT EmployeeSalary
FROM Employees
ORDER BY EmployeeSalary DESC
LIMIT 1 OFFSET N-1;

Example

Following is the SQL query for 2^nd highest salary

SELECT DISTINCT EmployeeSalary 
FROM Employees 
ORDER BY EmployeeSalary DESC 
LIMIT 1 OFFSET 1;

Similarly, Following query retrieves 3^rd highest salary

SELECT DISTINCT EmployeeSalary 
FROM Employees 
ORDER BY EmployeeSalary DESC 
LIMIT 1 OFFSET 2;

Using Correlated Subquery

Following is the approach for query creation

• Create a sub-query to count no. of unique salaries greater than the specified salary, i.e., the N-1 row has a higher salary than that specified salary.
• Combine with a main query using the WHERE clause to match N-1 counts of higher salary.

Syntax

Following is the query to find the N^th highest salary in SQL using the correlated subquery

SELECT EmployeeSalary
FROM Employees AS e1
WHERE N-1 = (
   SELECT COUNT(DISTINCT EmployeeSalary)
   FROM Employees AS e2
   WHERE e2.EmployeeSalary > e1.EmployeeSalary
);

Example

Following is the SQL correlated subquery query for 2^nd highest salary

SELECT EmployeeSalary 
FROM Employees AS e1 
WHERE 1 = (
   SELECT COUNT(DISTINCT EmployeeSalary) 
   FROM Employees AS e2 
   WHERE e2.EmployeeSalary > e1.EmployeeSalary
);

Similarly, following is the correlated SQL subquery for 3^rd highest salary

SELECT EmployeeSalary 
FROM Employees AS e1 
WHERE 2 = (
   SELECT COUNT(DISTINCT EmployeeSalary) 
   FROM Employees AS e2 
   WHERE e2.EmployeeSalary > e1.EmployeeSalary
);

Using DENSE_RANK() function

Approach for query creation -

• Use ORDERBY with descending order to arrange the highest salary on 1^st row
• Identify the rank of each row which was ordered using the DENSE_RANK() function
• Apply WHERE condition to fetch N^th highest salary

DENSE_RANK() function:

The output of the function is rank, which is calculated as

rank of a specific row = 1 + number of distinct rank values that appear before that specific row

Hence, the DENSE_RANK function allocates ranks to rows, assigning 1 to the first row and so on.

The record duplicate is already handled by the DENSE_RANK function because the function identifies rank with distinct records.

Raw Query

SELECT EmployeeSalary FROM (
   SELECT EmployeeSalary, DENSE_RANK() 
   OVER (ORDER BY EmployeeSalary DESC) 
   AS salary_rank
   FROM Employees
) AS ranked_salaries
WHERE salary_rank = N;

Example

SELECT EmployeeSalary FROM (
   SELECT EmployeeSalary, DENSE_RANK() 
   OVER (ORDER BY EmployeeSalary DESC) 
   AS salary_rank
   FROM Employees
) AS ranked_salaries
WHERE salary_rank = 2;

SQL query for 3^rd highest salary

SELECT EmployeeSalary FROM (
   SELECT EmployeeSalary, DENSE_RANK() 
   OVER (ORDER BY EmployeeSalary DESC) 
   AS salary_rank
   FROM Employees
) AS ranked_salaries
WHERE salary_rank = 3;

Conclusion

Any of them techniques can be used according to specific requirements but DENSE_RANK() function is suggested to obtain better performance in a larger number of records. All the above methods are well handled with the condition of duplicate records hence you always get correct results although there are duplicate salary amounts of different Employees.