STD(expression)

STDDEV(expression)

STD()函數是用於返回表達的標準偏差。 這相當於服用表達的VARIANCE()的平方根。下麵的例子計算CARS表列價格的標準差：

SQL>SELECT STD(PRICE) STD_DEVIATION FROM CARS;
+---------------------------------------------------------+
| STD_DEVIATION                                           |
+---------------------------------------------------------+
| 7650.2146                                               |
+---------------------------------------------------------+
1 row in set (0.00 sec)