使用 BigQuery SQL 计算列中重复记录之间的不同记录

Question

我在下面的表中有一列

| Column A | Column B |
| Active   | 202211210423 |
|   XYZ    | 202211210424 |
|   XYZ    | 202211210424 |
...

|   PQR    | 202211210426 |
| Active   | 202211210523 |
| abc      | 202211210525 |

Table_Input

如何计算 A 列中“活动”之间的不同记录？

输出可以像，COLUMN C 是“Active”之间的不同计数。

| Column A | Column B     | Column C |
| Active   | 202211210423 | x
|   XYZ    | 202211210424 | 24
|   XYZ    | 202211210424 | 24
...

|   PQR    | 202211210426 | 24 
| Active   | 202211210523 | 24
| abc      | 202211210525 | y 

Expected_output

我们可以使用分析函数来做到这一点吗？

我尝试使用 FIRST_VALUE 函数它没有用，因为它们都会第一次出现 Active。

输入字段 1

输出 2

Answer 1

不确定我清楚地了解您的要求，但您可以考虑以下内容。

SELECT * EXCEPT(agg, part),
       (SELECT COUNT(DISTINCT x.timestamp) FROM t.agg x WHERE x.colB <> 'Active') Count,
  FROM (
    SELECT *, ARRAY_AGG(STRUCT(timestamp, colB)) OVER (PARTITION BY colA, part) agg FROM (
      SELECT *, COUNT(1) OVER w0 - COUNTIF(colB <> 'Active') OVER w1 AS part
        FROM sample_data
      WINDOW w0 AS (PARTITION BY colA ORDER BY timestamp ROWS BETWEEN UNBOUNDED PRECEDING AND CURRENT ROW),
             w1 AS (PARTITION BY colA ORDER BY timestamp ROWS BETWEEN UNBOUNDED PRECEDING AND 1 PRECEDING)
    )
  ) t
 ORDER BY timestamp;

查询结果

Answer 2

首先我们在表tbl 中生成一些样本数据。

对于非重复计数，组标识符很有用，创建为 row_group 。然后单独查看每个分区。

with tbl as (select *, 1000+cast(rand()*5 as int64)+10*row_number() over () as colB from unnest(["Active","Y","X","Active","Y","Z","X","Active"])colA ),
helper as (select *, countif(colA="Active") over (order by colB rows between  unbounded preceding and 1 preceding) as row_group from tbl)
select *,
-1+count(distinct colA) over (partition by row_group)
 from helper

为了计算总数，这种方式更容易： 然后我们通过colB的顺序创建一个带有行号的helper表。必须为 unbounded preceding 和 unbounded following 找到此行号的最小值和最大值。减法给出这些关键词之间的总量。

with tbl as (select *, 1000+cast(rand()*5 as int64)+10*row_number() over () as colB from unnest(["Active","Y","X","Active","Y","Z","X","Active"])colA ),
helper as (select *, row_number() over (order by colB) as row_id from tbl)
select *,
min(if(colA="Active",row_id,null)) over (order by colB rows between current row and unbounded following)-
ifnull(max(if(colA="Active",row_id,null)) over (order by colB rows between unbounded preceding and 1 preceding),0)
 from helper