# How does MySQL calculate statistics such as average and total sum of query results?

In MySQL, aggregate functions can be used to calculate statistical information such as averages and sums of query results. Here are some commonly used aggregate functions:

- Calculate the average of a column.

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

- SUM: Calculate the total sum of a column.

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

- COUNT: calculate the number of rows in a column

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

- MAX: Calculate the maximum value of a column.

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

- MIN: Calculate the minimum value of a column.

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

It is important to note that when using aggregate functions, it is usually necessary to include a GROUP BY clause in the SELECT statement to specify which columns to group the calculations by. Additionally, the results can also be filtered using the HAVING clause.