All Functions
WHERE Clause
FUNCTION: AVG
SELECT AVG(field) AS [expression]
FROM table
[WHERE ...]
The
AVG
function is one of the aggregate functions that are used to calculate statistical information for a specified numeric field in a query. The other aggregate functions are:
COUNT, MAX, MIN, STDEV, STDEVP, SUM, VAR, VARP
. Note that all of these functions return a single value.
The
AVG
function simply calculates the arithmetic mean (i.e., the sum of the values divided by the number of values). Values which are
NULL
are not included in the calculations. If the field is just an empty set, no average will be calculated.
This code finds the average hospital stay of those MediCare patients over the age of 65:
SELECT AVG(DaysInHospital) AS [AverageStay]
FROM MediCarePatients
WHERE age > 65
Copyright 1999-2001 by Infinite Software Solutions, Inc. All rights reserved.
Trademark Information