测试用的数据
1. sum(LABST) over()
2. sum(LABST) over(order by MATNR)
3.sum(LABST) over(order by MATNR,ZWEEK)
4.sum(LABST) over(partition by MATNR order by MATNR)
5.sum(LABST) over(partition by MATNR order by MATNR,ZWEEK)
sum() over( partition by order by )
原文：https://www.cnblogs.com/lgx5/p/13156600.html