COUNT

Returns the number of rows matching the query criteria.

SELECT COUNT(*) FROM USERS WHERE Column2 = 'Bob'

COUNT(DISTINCT)

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

SELECT COUNT(DISTINCT Id) AS DistinctValues FROM USERS WHERE Column2 = 'Bob'

AVG

Returns the average of the column values.

SELECT Username, AVG(AnnualRevenue) FROM USERS WHERE Column2 = 'Bob'  GROUP BY Username

MIN

Returns the minimum column value.

SELECT MIN(AnnualRevenue), Username FROM USERS WHERE Column2 = 'Bob' GROUP BY Username

MAX

Returns the maximum column value.

SELECT Username, MAX(AnnualRevenue) FROM USERS WHERE Column2 = 'Bob' GROUP BY Username

SUM

Returns the total sum of the column values.

SELECT SUM(AnnualRevenue) FROM USERS WHERE Column2 = 'Bob'