擅长:python、mysql、java
<p>有两种类型的标准偏差-请参考:<a href="https://math.stackexchange.com/questions/15098/sample-standard-deviation-vs-population-standard-deviation">https://math.stackexchange.com/questions/15098/sample-standard-deviation-vs-population-standard-deviation</a></p>
<p>类似的问题-
<a href="https://stackoverflow.com/questions/31789939/calculate-the-standard-deviation-of-grouped-data-in-a-spark-dataframe">Calculate the standard deviation of grouped data in a Spark DataFrame</a></p>
<p>配置单元中的<code>stddev()</code>是指向<code>stddev_samp()</code>的指针。<code>stddev_pop()</code>是您要查找的(从代码的第2部分推断)。所以您的sql查询应该是<code>select stddev_pop(temperature) as stdtemp from washing</code></p>