MySQL STD()函數

STD(expression)

STDDEV(expression)

STD()函數用於返回表達式的標準差。這是相當於采取的方差的表達的VARIANCE()。下麵的示例計算價格的標準差列在我們的CARS：

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