SQL AVG() Function

The AVG() function in SQL is used to calculate the average value of a numeric column in a table. Here's a detailed explanation with examples:

Syntax

SELECT AVG(column_name) FROM table_name;

Example 1: Basic Usage

Consider a table employees with the following data:

To find the average salary of all employees:

SELECT AVG(salary) AS average_salary FROM employees;

Output:

Example 2: Using AVG() with a WHERE Clause

To find the average salary of employees with a salary greater than 50000:

SELECT AVG(salary) AS average_salary FROM employees WHERE salary > 50000;

Output:

Example 3: Grouping Results with AVG()

Consider another table sales with the following data:

To find the average sales amount by region:

SELECT region, AVG(sales_amount) AS average_sales FROM sales GROUP BY region;

Output:

Example 4: Combining AVG() with Other Aggregate Functions

To find the total sales and the average sales amount by region:

SELECT region, SUM(sales_amount) AS total_sales, AVG(sales_amount) AS average_sales FROM sales GROUP BY region;

Output:

These examples illustrate how the AVG() function can be used in various scenarios to compute average values in SQL.