# AVG

From SQLZOO

AVG(f) | ||
---|---|---|

Engine | OK | Alternative |

ingres | Yes | |

mysql | Yes | |

oracle | Yes | |

postgres | Yes | |

sqlserver | Yes |

# AVG

AVG gives the average (the mean) of a whole column or a group of rows for a single column of values.

AVG is an aggregate function it is normally used with GROUP BY.

The mean of the values 2, 5, 5 is (2+5+5)/3 = 12/3 = 4, you divide by 3 because there are 3 numbers in this example.

NULL values do not contribute to the calculation.

SELECT region, AVG(population) FROM bbc GROUP BY region

With a `GROUP BY region`

statement each region shows up just once.
The AVG column gives the average population per country for each region.

```
SELECT region, AVG(population)
FROM bbc
GROUP BY region
```

See also