LEFT OUTER JOIN 在 bigquery 上创建子查询时出错 [英] LEFT OUTER JOIN Error creating a subquery on bigquery

问题描述

我正在尝试从我 bq 上的事件表中评估 MAL、WAL 和 DAU...

I'm trying to eval MAL, WAL and DAU from a event table on my bq...

我创建一个查询查找 DAU 并与他一起查找 WAU 和 MAU，但它不起作用，我收到了这个错误:

I create a query find DAU and with him find WAU and MAU, but it does not work, i received this error:

LEFT OUTER JOIN cannot be used without a condition that is an equality of fields from both sides of the join.

这是我的问题

WITH dau AS (
  SELECT 
      date, 
      COUNT(DISTINCT(events.device_id)) as DAU_explorer         
  FROM `workspace.event_table` as events
  GROUP BY 1
)

SELECT  
  date, 
  dau, 
  (SELECT 
      COUNT(DISTINCT(device_id))  
     FROM `workspace.event_table` as events
     WHERE events.date BETWEEN DATE_ADD(dau.date, INTERVAL -30 DAY)  AND dau.date
     ) AS mau,
  (SELECT 
      COUNT(DISTINCT(device_id)) as DAU_explorer  
    FROM `workspace.event_table` as events
    WHERE events.date BETWEEN DATE_ADD(dau.date, INTERVAL -7 DAY)  AND dau.date
       ) AS wau
FROM dau

我的错误在哪里?不能在 bq 上运行这样的子查询吗?

Where is my error? Is not possible run subqueries like this on bq?

推荐答案

试试这个:

WITH data AS (
  SELECT DATE(creation_date) date, owner_user_id device_id
  FROM `bigquery-public-data.stackoverflow.posts_questions` 
  WHERE EXTRACT(YEAR FROM creation_date)=2017
)

#standardSQL
SELECT DATE_SUB(date, INTERVAL i DAY) date_grp
 , COUNT(DISTINCT IF(i<31,device_id,null)) unique_30_day_users
 , COUNT(DISTINCT IF(i<8,device_id,null)) unique_7_day_users
FROM `data`, UNNEST(GENERATE_ARRAY(1, 30)) i
GROUP BY 1
ORDER BY date_grp
LIMIT 100
OFFSET 30

如果您正在寻找更有效的解决方案，请尝试近似结果.

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