SQL从标志中获取2个相邻的动作

如何解决SQL从标志中获取2个相邻的动作

希望你一切顺利！

我有一个虚拟数据如下。

我想从每个用户的标志中获取 2 个相邻的操作。

这是描述我想法的图表。

这是我想要的：

如何实现 sql（我使用 Google Bigquery）？ 希望有人能点亮我。感谢一百万！

解决方法

您似乎想要lag()。我会将“动作序列”保留为两个单独的列：

select user,prev_action,action,flag
from (select t.*,lag(action) over (partition by user order by sequence) as prev_action
      from t
     ) t
where prev_action is not null;

,

考虑以下选项

select user,actions.action_sequence,flag  from (
  select *,(
    select as struct count(1) actions_count,string_agg(action,' >> ' order by sequence) action_sequence
    from unnest(arr)
    ) actions
  from (
    select *,array_agg(struct(action,sequence)) 
      over(partition by user order by sequence desc range between current row and 1 following) arr
    from src_table
  ) 
)
where flag != '' 
and actions.actions_count = 2
# order by user,sequence      

如果应用于您问题中的样本数据 - 输出为

注意 - 上述解决方案可重复用于您想要分析的任意数量的序列 - 不像其他答案中的解决方案仅限于两个

在此解决方案中 - 您只需将下面几行中的数字（分别为 1 和 2）更改为您需要的任何内容，无需其他更改:o)

over(partition by user order by sequence desc range between current row and 1 following) arr               

和

and actions.actions_count = 2

例如，如果您将它们分别更改为 2 和 3 - 输出将是

,

试试导航功能LAG：

WITH finishers AS
 (SELECT 'Sophia Liu' as name,TIMESTAMP '2016-10-18 2:51:45' as finish_time,'F30-34' as division
  UNION ALL SELECT 'Lisa Stelzner',TIMESTAMP '2016-10-18 2:54:11','F35-39'
  UNION ALL SELECT 'Nikki Leith',TIMESTAMP '2016-10-18 2:59:01','F30-34'
  UNION ALL SELECT 'Lauren Matthews',TIMESTAMP '2016-10-18 3:01:17','F35-39'
  UNION ALL SELECT 'Desiree Berry',TIMESTAMP '2016-10-18 3:05:42','F35-39'
  UNION ALL SELECT 'Suzy Slane',TIMESTAMP '2016-10-18 3:06:24','F35-39'
  UNION ALL SELECT 'Jen Edwards',TIMESTAMP '2016-10-18 3:06:36','F30-34'
  UNION ALL SELECT 'Meghan Lederer',TIMESTAMP '2016-10-18 3:07:41','F30-34'
  UNION ALL SELECT 'Carly Forte',TIMESTAMP '2016-10-18 3:08:58','F25-29'
  UNION ALL SELECT 'Lauren Reasoner',TIMESTAMP '2016-10-18 3:10:14','F30-34')
SELECT name,finish_time,division,LAG(name)
    OVER (PARTITION BY division ORDER BY finish_time ASC) AS preceding_runner
FROM finishers;

+-----------------+-------------+----------+------------------+
| name            | finish_time | division | preceding_runner |
+-----------------+-------------+----------+------------------+
| Carly Forte     | 03:08:58    | F25-29   | NULL             |
| Sophia Liu      | 02:51:45    | F30-34   | NULL             |
| Nikki Leith     | 02:59:01    | F30-34   | Sophia Liu       |
| Jen Edwards     | 03:06:36    | F30-34   | Nikki Leith      |
| Meghan Lederer  | 03:07:41    | F30-34   | Jen Edwards      |
| Lauren Reasoner | 03:10:14    | F30-34   | Meghan Lederer   |
| Lisa Stelzner   | 02:54:11    | F35-39   | NULL             |
| Lauren Matthews | 03:01:17    | F35-39   | Lisa Stelzner    |
| Desiree Berry   | 03:05:42    | F35-39   | Lauren Matthews  |
| Suzy Slane      | 03:06:24    | F35-39   | Desiree Berry    |
+-----------------+-------------+----------+------------------+