如何從teradata中的當前行值中減去所有以前的行值？

Question

如何從teradata中的當前行值中減去所有以前的行值？列值不是整數格式。

Answer 1

你應該學會的Teradata OLAP Functions..and嘗試如下： -

select COL1,COL2 , 
    coalesce(min(col2) over (partition by col1 order by col2 rows between 1 preceding and 1 preceding), 0) as prv_value 
col2-prv_value as diff 
    from TEMP