Compatibility
| AVG(f) |
| Engine |
OK |
Alternative |
| ingres |
yes |
|
| mysql |
yes |
|
| oracle |
yes |
|
| postgres |
yes |
|
| sqlserver |
yes |
|
AVGAVG 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.
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Results
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See also: |