In SQL, there are two built-in functions to sum or average the data in your table.

In this article I will show you how to use the `SUM` and `AVG` functions in SQL using code examples.

## How to use the SUM function in SQL

If you need to add a group of numbers in your table you can use the `SUM` function in SQL.

This is the basic syntax:

``SELECT SUM(column_name) FROM table_name;``

The `SELECT` statement in SQL tells the computer to get data from the table.

The `FROM` clause in SQL specifies which table we want to list.

In this example, we have a table called `students` with the columns of `id`, `name`, `date`, and `total`. We want to add up the total number of candy bars sold by all of the students.

We can use this syntax to get the total number of candy bars sold:

``````SELECT SUM(total) FROM students;
``````

The result would be 41.

We can also get the sum for each student using the `GROUP BY` clause.

The first part is to select the name and sum for the total number of candy bars sold, like this:

``SELECT name, SUM(total)``

The second part is to group the sum by name:

``FROM students GROUP BY name;``

Here is the complete code to group the total number of candy bars sold by student name.

``````SELECT name, SUM(total) FROM students GROUP BY name;
``````

This is what the result would look like in our table:

Right now the results are grouped alphabetically by student name.

We can modify the code to sort the list of results from largest total to smallest using the `ORDER BY` clause.

``SELECT name, SUM(total) FROM students GROUP BY name ORDER BY total DESC;``

The `DESC` keyword tells the computer to sort from largest to smallest total.

If we wanted to sort the total from smallest to largest, then we would omit the `DESC` keyword.

``````SELECT name, SUM(total) FROM students GROUP BY name ORDER BY total;
``````

## How to use the AVG function in SQL

The `AVG` function finds the arithmetic mean for a group of records in a SQL table. An average, or arithmetic mean, is the sum of a group of numbers divided by the count for that group.

For example, 2+4+4+6+6+8 is 30 divided 6 which results in an average of 5.

This is the basic syntax for the `AVG` function:

``````SELECT AVG(column_name) FROM table_name;
``````

In this example, we have a table called `students`, with columns of `id` , `name`, `date`, and `scores`.  We want to find the average of all the students' test scores in our table.

We have to use this syntax to get the average for the test scores:

``SELECT AVG(scores) FROM students; ``

The average would be 85.333.

We can also use the `ROUND` function to round our result to the nearest integer.

``SELECT ROUND(AVG(scores)) FROM students; ``

We can also get the average for each student using the `GROUP BY` clause.

The first part is to select the name and average for the scores, like this:

``SELECT name, ROUND(AVG(scores))``

The second part is to group the average scores by name:

``FROM students GROUP BY name;``

This is what the code looks like all together:

``SELECT name, ROUND(AVG(scores)) FROM students GROUP BY name;``

This is what the result looks like in the table:

## Conclusion

There may be times were you need to find the sum or average of records in your table.

If you need to add a group of numbers in your table you can use the `SUM` function in SQL.

This is the basic syntax:

``SELECT SUM(column_name) FROM table_name;``

If you need to arrange the data into groups, then you can use the `GROUP BY` clause.

The `AVG` function finds the arithmetic mean for a group of records in a SQL table. An average, or arithmetic mean, is the sum of a group of numbers divided by the count for that group.

This is the basic syntax.

``````SELECT AVG(column_name) FROM table_name;
``````

I hope you enjoyed this tutorial and best of luck on your SQL journey.