SQL学习——窗口函数
当orderby和窗口从句都缺失，窗口规范默认是rowsbetweenunboundedprecedingandunboundedfollowing所有的数据。#orderby后面缺少窗口从句条件,窗口默认规范是rowsbetweenunboundedprecedingandcurrentrow.当前行和之前。函数名（[expr]）over(partitionby)orderbyrowsbetween)...
