Kusto查询，按键计算值的百分比

Question

我想按键计算值的百分比。举个例子，给定一个类似于的表格

datatable (key: string, value: string) 
[ 
"a","1",
"a","2",
"b","x",
"b","x",
"b","x",
"b","y",
]

我想得到这样的结果：

[
"a","1",.5,
"a","2",.5,
"b","x",.75,
"b","y",.25,
]

我知道如何使用as和toscalar来获得所有键的值百分比，但我不知道如何通过键来实现这一点。

Answer 1

我们需要在两个级别的中使用聚合之间的联接

datatable (key: string, value: string) 
[ 
"a","1",
"a","2",
"b","x",
"b","x",
"b","x",
"b","y",
]
| summarize count() by key, value
| as summarize_by_key_value
| summarize sum(count_) by key
| join kind=inner summarize_by_key_value on key
| project key, value, percentage = 1.0 * count_ / sum_count_

键		值	百分比
a	1	0.5
a	2	0.5
b	x	0.75
b	y	0.25