Examples of Aggregate Functions

Below are several examples of SQL aggregate functions. You can use these with a GROUP BY clause to aggregate rows based on the specified GROUP BY criterion. This can be a reporting tool.

COUNT

Returns the number of rows matching the query criteria.

SELECT COUNT(*) FROM Files WHERE FileId = '119116'

COUNT(DISTINCT)

Returns the number of distinct, non-null field values matching the query criteria.

SELECT COUNT(DISTINCT FileId) AS DistinctValues FROM Files WHERE FileId = '119116'

AVG

Returns the average of the column values.

SELECT ChildrenNum, AVG(Length) FROM Files WHERE FileId = '119116' GROUP BY ChildrenNum

MIN

Returns the minimum column value.

SELECT MIN(Length), ChildrenNum FROM Files WHERE FileId = '119116' GROUP BY ChildrenNum

MAX

Returns the maximum column value.

SELECT ChildrenNum, MAX(Length) FROM Files WHERE FileId = '119116' GROUP BY ChildrenNum

SUM

Returns the total sum of the column values.

SELECT SUM(Length) FROM Files WHERE FileId = '119116'

COUNT

Returns the number of rows matching the query criteria.

SELECT COUNT(*) FROM Files WHERE FileId = '119116'

COUNT(DISTINCT)

Returns the number of distinct, non-null field values matching the query criteria.

SELECT COUNT(DISTINCT FileId) AS DistinctValues FROM Files WHERE FileId = '119116'

AVG

Returns the average of the column values.

SELECT ChildrenNum, AVG(Length) FROM Files WHERE FileId = '119116'  GROUP BY ChildrenNum

MIN

Returns the minimum column value.

SELECT MIN(Length), ChildrenNum FROM Files WHERE FileId = '119116' GROUP BY ChildrenNum

MAX

Returns the maximum column value.

SELECT ChildrenNum, MAX(Length) FROM Files WHERE FileId = '119116' GROUP BY ChildrenNum

SUM

Returns the total sum of the column values.

SELECT SUM(Length) FROM Files WHERE FileId = '119116'