Question

我已在网站上运行Google Analytics，现在正尝试在特定时间间隔内确定转化率。因此，我有一个包含

的表

interval_id
i.interval_start_time_utc
i.interval_stop_time_utc

可悲的是，以下将每个订单分配给某个间隔的BigQuery查询将不起作用：

SELECT
totals.transactions,
totals.visits,
i.interval_id
FROM [123456.ga_sessions_20160609]
INNER JOIN intervals i ON i.interval_start_time_utc < visitStartTime AND visitStartTime < i.interval_end_time_utc

这会引发错误

ON clause must be AND of = comparisons of one field name from each table [...]

所以我认为BigQuery根本不做范围连接。还有另一种方法可以做到这一点，不做完全加入，然后削减？对于这类事情，有完全不同的，更好的方法吗？

Answer 1

BigQuery Standard SQL没有此限制 - 请参阅Enabling Standard SQL

如果您想使用BigQuery Legacy SQL - 请尝试下面的内容

SELECT
  totals.transactions,
  totals.visits,
  i.interval_id
FROM [123456.ga_sessions_20160609]
CROSS JOIN intervals i 
WHERE i.interval_start_time_utc < visitStartTime 
AND visitStartTime < i.interval_end_time_utc

Answer 2

为了呈现想法 - 让我们简化示例
让我们记住 - 我们确实希望使用BigQuery Legacy SQL - 而不是标准SqL，它是微不足道的！

挑战

假设我们有visits表：

SELECT visit_time FROM 
  (SELECT 2 AS visit_time),
  (SELECT 12 AS visit_time),
  (SELECT 22 AS visit_time),
  (SELECT 32 AS visit_time)

和intervals表：

SELECT before, after, event FROM 
  (SELECT 1 AS before, 5 AS after, 3 AS event),
  (SELECT 6 AS before, 10 AS after, 8 AS event),
  (SELECT 21 AS before, 25 AS after, 23 AS event),
  (SELECT 33 AS before, 37 AS after, 35 AS event)

我们希望提取事件before和after值

内的所有访问次数

这可以通过使用CROSS JOIN完成，如下所示：

SELECT
  visit_time, event, before, after
FROM (
  SELECT visit_time FROM 
    (SELECT 2 AS visit_time),
    (SELECT 12 AS visit_time),
    (SELECT 22 AS visit_time),
    (SELECT 32 AS visit_time),
) AS visits
CROSS JOIN (
  SELECT before, after, event FROM 
    (SELECT 1 AS before, 5 AS after, 3 AS event),
    (SELECT 6 AS before, 10 AS after, 8 AS event),
    (SELECT 21 AS before, 25 AS after, 23 AS event),
    (SELECT 33 AS before, 37 AS after, 35 AS event)
) AS intervals
WHERE visit_time BETWEEN before AND after

结果为：

visit_time  event   before  after    
2           3       1       5    
22          23      21      25

潜在问题

当两个表都足够大时 - 这个交叉连接变得相当昂贵！

提示

碰巧（来自用户的评论） - 间隔始终是事件左右两侧的x个单位。

解决方案

以下是使用提示/事实的建议解决方案/选项，并在两个大表之间使用JOIN而不是CROSS JOIN

这里的关键是生成（动态）新表，该表将根据事件和x

保存所有可能的间隔值

SELECT event, event + delta AS point 
FROM (
  SELECT event FROM
    (SELECT 1 AS before, 5 AS after, 3 AS event),
    (SELECT 6 AS before, 10 AS after, 8 AS event),
    (SELECT 21 AS before, 25 AS after, 23 AS event),
    (SELECT 33 AS before, 37 AS after, 35 AS event)
) AS events
CROSS JOIN (
  SELECT pos - 1 - 2 AS delta FROM (
       SELECT ROW_NUMBER() OVER() AS pos, * FROM (FLATTEN((
       SELECT SPLIT(RPAD('', 1 + 2 * 2, '.'),'') AS h FROM (SELECT NULL)),h
  )))   
) AS deltas

在上面的代码中x = 2 - 但你可以在两个地方改变它，例如如果x = 5你应该有

SELECT pos - 1 - 5 AS delta FROM (
     SELECT ROW_NUMBER() OVER() AS pos, * FROM (FLATTEN((
     SELECT SPLIT(RPAD('', 1 + 2 * 5, '.'),'') AS h FROM (SELECT NULL)),h
)))

以上代码中的CROSS JOIN很便宜，因为增量表非常小

所以，最后，你可以在下面找到你的结果：

SELECT
  visit_time, event 
FROM (
  SELECT visit_time FROM 
    (SELECT 2 AS visit_time),
    (SELECT 12 AS visit_time),
    (SELECT 22 AS visit_time),
    (SELECT 32 AS visit_time),
) AS visits
JOIN (
  SELECT event, event + delta AS point 
  FROM (
    SELECT event FROM
      (SELECT 1 AS before, 5 AS after, 3 AS event),
      (SELECT 6 AS before, 10 AS after, 8 AS event),
      (SELECT 21 AS before, 25 AS after, 23 AS event),
      (SELECT 33 AS before, 37 AS after, 35 AS event)
  ) AS events
  CROSS JOIN (
    SELECT pos - 1 - 2 AS delta FROM (
         SELECT ROW_NUMBER() OVER() AS pos, * FROM (FLATTEN((
         SELECT SPLIT(RPAD('', 1 + 2 * 2, '.'),'') AS h FROM (SELECT NULL)),h
    )))   
  ) AS deltas
) AS points
ON points.point = visits.visit_time

预期结果

visit_time  event    
2           3    
22          23

我认为上述方法可以为您服务 - 但您确定需要将其应用于您的特定情况我认为如果您将所有相关时间都计算到相应的分钟

，这可以相对容易地完成

希望这会有所帮助如果您能得到这项工作，请与我们分享结果：o）

Google Analytics：时间间隔内的转化率

2 个答案: