COUNT

Returns the number of rows matching the query criteria.

SELECT COUNT(*) FROM RSSFeed WHERE Title = 'US'

COUNT(DISTINCT)

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

SELECT COUNT(DISTINCT Guid) AS DistinctValues FROM RSSFeed WHERE Title = 'US'

AVG

Returns the average of the column values.

SELECT Author, AVG(AnnualRevenue) FROM RSSFeed WHERE Title = 'US'  GROUP BY Author

MIN

Returns the minimum column value.

SELECT MIN(AnnualRevenue), Author FROM RSSFeed WHERE Title = 'US' GROUP BY Author

MAX

Returns the maximum column value.

SELECT Author, MAX(AnnualRevenue) FROM RSSFeed WHERE Title = 'US' GROUP BY Author

SUM

Returns the total sum of the column values.

SELECT SUM(AnnualRevenue) FROM RSSFeed WHERE Title = 'US'