在 BigQuery 中为选定列创建统计信息摘要

Question

我正在尝试从几个数字列中总结一些静态属性，例如连续分位数、均值、标准差等，然后将它们包装到行中，并将原始列名作为附加列附加。我知道使用AVG、STDDEV_PO、PERCENTILE_CONT... 从单个列中获取它们，但没有找到关于同时在多个列上执行它们的文章/食谱。有什么想法吗？

示例输入：

ID	Col1	Col2	Col3
1	1.0	2.0	4.0
2	2.0	4.0	8.0
3	3.0	6.0	12.0
4	4.0	8.0	16.0

预期输出：

Col Name	Q1	Q2	Q3	Mean	Std
Col1	1.75	2.5	3.25	2.5	1.12
Col2	3.5	5.0	6.5	5.0	2.24
Col3	7.0	10.0	13.0	10.0	4.47

或“转置”版本：

Stats	Col1	Col2	Col3
Q1	1.75	3.5	7.0
Q2	2.5	5.0	10.0
Q3	3.25	6.5	13.0
Mean	2.5	5.0	10.0
Std	1.12	2.24	4.47

Answer 1

考虑下面

select distinct col, 
  percentile_cont(value, 0.25) over win as q1,
  percentile_cont(value, 0.50) over win as q2,
  percentile_cont(value, 0.75) over win as q3,
  avg(value) over win as avg, 
  stddev_pop(value) over win as std, 
from your_table
unpivot (value for col in (col1, col2, col3))
window win as (partition by col)                 

如果应用于您问题中的样本数据 - 输出是

要获得“转置”版本 - 在下面使用

select * from (
  select * from (
    select distinct col, 
      percentile_cont(value, 0.25) over win as q1,
      percentile_cont(value, 0.50) over win as q2,
      percentile_cont(value, 0.75) over win as q3,
      avg(value) over win as avg, 
      stddev_pop(value) over win as std, 
    from data
    unpivot (value for col in (col1, col2, col3))
    window win as (partition by col)
  ) unpivot (value for stats in (q1, q2, q3, avg, std))
) pivot (any_value(value) for col in ('col1', 'col2', 'col3'))

在这种情况下 - 输出是