COUNT

Returns the number of rows matching the query criteria.

SELECT COUNT(*) FROM Customer WHERE CustomerId = '12345'

COUNT(DISTINCT)

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

SELECT COUNT(DISTINCT Name) AS DistinctValues FROM Customer WHERE CustomerId = '12345'

AVG

Returns the average of the column values.

SELECT TotalDue, AVG(AnnualRevenue) FROM Customer WHERE CustomerId = '12345'  GROUP BY TotalDue

MIN

Returns the minimum column value.

SELECT MIN(AnnualRevenue), TotalDue FROM Customer WHERE CustomerId = '12345' GROUP BY TotalDue

MAX

Returns the maximum column value.

SELECT TotalDue, MAX(AnnualRevenue) FROM Customer WHERE CustomerId = '12345' GROUP BY TotalDue

SUM

Returns the total sum of the column values.

SELECT SUM(AnnualRevenue) FROM Customer WHERE CustomerId = '12345'