COUNT

Returns the number of rows matching the query criteria.

SELECT COUNT(*) FROM WorkItems WHERE Reason = 'Manual'

COUNT(DISTINCT)

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

SELECT COUNT(DISTINCT Id) AS DistinctValues FROM WorkItems WHERE Reason = 'Manual'

AVG

Returns the average of the column values.

SELECT BuildNumber, AVG(AnnualRevenue) FROM WorkItems WHERE Reason = 'Manual'  GROUP BY BuildNumber

MIN

Returns the minimum column value.

SELECT MIN(AnnualRevenue), BuildNumber FROM WorkItems WHERE Reason = 'Manual' GROUP BY BuildNumber

MAX

Returns the maximum column value.

SELECT BuildNumber, MAX(AnnualRevenue) FROM WorkItems WHERE Reason = 'Manual' GROUP BY BuildNumber

SUM

Returns the total sum of the column values.

SELECT SUM(AnnualRevenue) FROM WorkItems WHERE Reason = 'Manual'