我有一个要求,需要计算Azure Data Explorer中每行之间的累积差异。
以下是样本数据
ID | NAME | Value
---+---------+-------------
1 | ABC | 1987698.987
2 | DEF | 1987870.987
3 | GHI | 1987990.987
4 | JKL | 1988200.987
预期结果输出:
ID | NAME | Value | Cumulative_difference
---+-------+-------------+----------------------
1 | ABC | 1987698.987 | 0
2 | DEF | 1987870.987 | 172
3 | GHI | 1987990.987 | 120
4 | JKL | 1988200.987 | 210
提前感谢
您可以使用prev((函数,例如
datatable(ID:int, NAME:string, Value:double)
[1, "ABC", 1987698.987,
2, "DEF", 1987870.987,
3, "GHI", 1987990.987,
4, "JKL", 1988200.987]
| order by ID asc
| extend Cumulative_difference = coalesce(Value - prev(Value), double(0))
ID | 名称 | 值 | 累积差||
---|---|---|---|---|
1 | ABC | |||
2 | DEF | 1987870.987 | 172 | |
3 | GHI | >1987990.987 | 120 | |
4 | JKL | 1988200.987 | 210 |