SQL AVG() Function

The SQL AVG() Function

In SQL, the AVG() function is an aggregate function used to calculate the average value of a set of values in a column. It operates on a column of numerical data and returns the average of all the values in that column.

Here's the syntax for using the AVG() function:

    SELECT AVG(column_name)
    FROM table_name;
    

Example:

Let's say we have a table called sales with a column named amount representing the sales amount for each transaction. We want to find the average sales amount:

    SELECT AVG(amount) AS average_sales_amount
    FROM sales;
    

In this example:

• AVG(amount) calculates the average of all values in the amount column.
• AS average_sales_amount assigns a name to the calculated average, which can be used to reference the result.

The AVG() function can also be combined with other clauses such as GROUP BY to calculate averages for groups of rows based on certain criteria.

Example:

Let's say we want to find the average sales amount for each product category:

    SELECT product_category, AVG(amount) AS average_sales_amount
    FROM sales
    GROUP BY product_category;
    

In this example:

• GROUP BY product_category groups the rows by the product_category column.
• AVG(amount) calculates the average sales amount for each group of rows within each product category.