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SQL for beginners

Averaging values with AVG #

AVG is an aggregate function that computes the mean of a numeric column across all the rows.

SELECT
    AVG(column_name) AS average
FROM
    table_name;

AVG(column_name) adds up every value in column_name and divides by the number of rows. Like SUM, rows where the column is NULL are skipped rather than counted as zero.

Example #

SELECT
    AVG(age) AS average_age
FROM
    customers;

Result:

+--------------+
| average_age  |
+--------------+
|    71.6      |
+--------------+

This tells us the mean age across all rows in customers.

Exercise #

Write a command that computes the average price across every row in the products table.

  • The result has an average_price column.
  • The value of average_price matches the average of the price column in products.
Solution 
SELECT
    AVG(price) AS average_price
FROM
    products;
Output will be displayed here