COUNT

クエリ条件に一致する行の数を返します。

SELECT COUNT(*) FROM Customers WHERE GivenName = 'Cook, Brian'

COUNT(DISTINCT)

クエリ条件に一致する、null 以外の個別のフィールド値の数を返します。

SELECT COUNT(DISTINCT Id) AS DistinctValues FROM Customers WHERE GivenName = 'Cook, Brian'

AVG

カラムの値の平均を返します。

SELECT GivenName, AVG(AnnualRevenue) FROM Customers WHERE GivenName = 'Cook, Brian'  GROUP BY GivenName

MIN

カラムの値の最小値を返します。

SELECT MIN(AnnualRevenue), GivenName FROM Customers WHERE GivenName = 'Cook, Brian' GROUP BY GivenName

MAX

カラムの値の最大値を返します。

SELECT GivenName, MAX(AnnualRevenue) FROM Customers WHERE GivenName = 'Cook, Brian' GROUP BY GivenName

SUM

カラムの値の合計を返します。

SELECT SUM(AnnualRevenue) FROM Customers WHERE GivenName = 'Cook, Brian'