COUNT

クエリ条件に一致する行の数を返します。

SELECT COUNT(*) FROM INVOICES WHERE CustomerName = 'NewTech Industries'

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 InvoiceId) AS DistinctValues FROM INVOICES WHERE CustomerName = 'NewTech Industries'

AVG

カラムの値の平均を返します。

SELECT InvoiceNumber, AVG(AnnualRevenue) FROM INVOICES WHERE CustomerName = 'NewTech Industries'  GROUP BY InvoiceNumber

MIN

カラムの値の最小値を返します。

SELECT MIN(AnnualRevenue), InvoiceNumber FROM INVOICES WHERE CustomerName = 'NewTech Industries' GROUP BY InvoiceNumber

MAX

カラムの値の最大値を返します。

SELECT InvoiceNumber, MAX(AnnualRevenue) FROM INVOICES WHERE CustomerName = 'NewTech Industries' GROUP BY InvoiceNumber

SUM

カラムの値の合計を返します。

SELECT SUM(AnnualRevenue) FROM INVOICES WHERE CustomerName = 'NewTech Industries'