Aggregate Functions

Aggregate Functions in SQL perform calculations on a set of values and return a single value. Examples include COUNT, SUM, AVG, MIN, and MAX. They operate on groups of rows to generate summary statistics or insights. These functions are commonly used for data analysis and reporting purposes. Aggregate Functions help summarize large datasets, providing valuable insights into the underlying data distribution.

 

COUNT: SQL COUNT aggregate function count all rows that meet the specified condition.

SELECT COUNT(*) AS total_employees FROM employees WHERE department = 'Sales';

In this example we're retrieving the total number of employees who belong to the 'Sales' department. This query provides a simple count of how many employees are associated with the specified department.

 

SUM: The SUM function adds up all the column values in the specified column.

SELECT SUM(salary) AS total_salary FROM employees WHERE department = 'Sales';

In this example we're retrieving the total salary expenditure for the 'Sales' department. This query provides a consolidated view of the total compensation paid to employees in that department.

 

AVG: The AVG function computes the sum of all column values and divides it by the total number of rows under the specified condition.

SELECT AVG(salary) AS average_salary FROM employees WHERE department = 'Sales';

In this example we're retrieving the average salary of employees in the 'Sales' department. This query provides insight into the average compensation level for employees in that specific department.

 

MIN: The MIN function identifies the smallest value in the specified column.

SELECT MIN(salary) AS lowest_salary FROM employees WHERE department = 'Sales';

In this example we're retrieving the lowest salary among employees in the 'Sales' department. This query provides insight into the minimum compensation level within that specific department.

 

MAX: The MAX function identifies the greatest value in the specified column.

SELECT MAX(salary) AS highest_salary FROM employees WHERE department = 'Sales';

In this example we're retrieving the highest salary among employees in the 'Sales' department. This query provides insight into the maximum compensation level within that specific department.