Question

我想在BigQuery中联接多个表，但是Joining multiple tables in bigquery的解决方案没有帮助我获得所需的输出。

我的出发点如下。我正在创建5个单独的表，这些表显示特定页面可能的每个评级值。在此处查看示例输出：

通过以下方式创建表：

#standardSQL
  CREATE TEMPORARY FUNCTION tables_in_range(suffix STRING) AS (suffix BETWEEN (
    SELECT
      FORMAT_DATE('%y%m%d',
        DATE('2018-06-01')))
    AND (
    SELECT
      FORMAT_DATE('%y%m%d',
        DATE('2018-06-30'))));

SELECT
  h.page.pagePath AS page,
  Count(h.eventInfo.eventLabel)as five_star
FROM
  `table.ga_sessions_20*` AS t,
  t.hits AS h
WHERE
  h.eventInfo.eventAction='rating'
  AND h.eventInfo.eventLabel ='5'
  AND tables_in_range(_TABLE_SUFFIX)
  AND REGEXP_CONTAINS(h.page.pagePath,
    r'/xyz/')
  AND h.type='EVENT'
group by 1

按此处所述Joining multiple tables in bigquery加入表时，很遗憾，没有得到预期的结果。相反，联接仅查看所有5个表具有相同之处的页面-意味着这些页面的评级在1-5个五个可能值中的每个值中。请参见下面的示例输出。 joint table results

select
five_star.page as page,
five_star.five_star as five_star,
four_star.four_star as four_star,
three_star.three_star as three_star,
two_star.two_star as two_star,
one_star.one_star as one_star
from five_star
join four_star using (page)
join three_star using (page)
join two_star using (page)
JOIN one_star using (page)

我想通过联接实现的是一个这样的表： desired output。我看到的问题是，如果页面未获得一定的评分，它将不会加入查询atm中。不幸的是，我无法找到Union all，Cross Join或left join的解决方案，因此我非常感谢这里的支持！

Answer 1

以下是用于BigQuery标准SQL

#standardSQL
SELECT 
  page,
  SUM(five_star_rating) five_star_rating,
  SUM(four_star_rating) four_star_rating,
  SUM(three_star_rating) three_star_rating,
  SUM(two_star_rating) two_star_rating,
  SUM(one_star_rating) one_star_rating
FROM (
  SELECT page, 0 one_star_rating, 0 two_star_rating, 0 three_star_rating, 0 four_star_rating, five_star_rating FROM `project.dataset.table5` UNION ALL
  SELECT page, 0, 0, 0, four_star_rating, 0 FROM `project.dataset.table4` UNION ALL
  SELECT page, 0, 0, three_star_rating, 0, 0 FROM `project.dataset.table3` UNION ALL
  SELECT page, 0, two_star_rating, 0, 0, 0 FROM `project.dataset.table2` UNION ALL
  SELECT page, one_star_rating, 0, 0, 0, 0 FROM `project.dataset.table1` 
)
GROUP BY page

您可以使用下面的问题中的虚拟数据进行测试，操作

#standardSQL
WITH `project.dataset.table5` AS (
  SELECT 'A' page, 1 five_star_rating UNION ALL
  SELECT 'B', 1 UNION ALL
  SELECT 'C', 1 
), `project.dataset.table4` AS (
  SELECT 'C' page, 1 four_star_rating UNION ALL
  SELECT 'D', 1 UNION ALL
  SELECT 'F', 1 
), `project.dataset.table3` AS (
  SELECT 'F' page, 1 three_star_rating UNION ALL
  SELECT 'G', 1 UNION ALL
  SELECT 'H', 1 
), `project.dataset.table2` AS (
  SELECT 'H' page, 1 two_star_rating UNION ALL
  SELECT 'I', 1 UNION ALL
  SELECT 'J', 1 
), `project.dataset.table1` AS (
  SELECT 'J' page, 1 one_star_rating UNION ALL
  SELECT 'K', 1 UNION ALL
  SELECT 'L', 1 
)
SELECT 
  page,
  SUM(five_star_rating) five_star_rating,
  SUM(four_star_rating) four_star_rating,
  SUM(three_star_rating) three_star_rating,
  SUM(two_star_rating) two_star_rating,
  SUM(one_star_rating) one_star_rating
FROM (
  SELECT page, 0 one_star_rating, 0 two_star_rating, 0 three_star_rating, 0 four_star_rating, five_star_rating FROM `project.dataset.table5` UNION ALL
  SELECT page, 0, 0, 0, four_star_rating, 0 FROM `project.dataset.table4` UNION ALL
  SELECT page, 0, 0, three_star_rating, 0, 0 FROM `project.dataset.table3` UNION ALL
  SELECT page, 0, two_star_rating, 0, 0, 0 FROM `project.dataset.table2` UNION ALL
  SELECT page, one_star_rating, 0, 0, 0, 0 FROM `project.dataset.table1` 
)
GROUP BY page

Answer 2

不幸的是，我无法通过Union all，Cross Join或left join ...找到解决方案...

另一种选择是使用FULL JOIN，如以下示例所示

#standardSQL
SELECT
  COALESCE(five_star.page, four_star.page, three_star.page, two_star.page, one_star.page) AS page,
  IFNULL(five_star.five_star_rating, 0) AS five_star,
  IFNULL(four_star.four_star_rating, 0) AS four_star,
  IFNULL(three_star.three_star_rating, 0) AS three_star,
  IFNULL(two_star.two_star_rating, 0) AS two_star,
  IFNULL(one_star.one_star_rating, 0) AS one_star
FROM `project.dataset.table5` five_star
FULL JOIN `project.dataset.table4` four_star USING (page)
FULL JOIN `project.dataset.table3` three_star USING (page)
FULL JOIN `project.dataset.table2` two_star USING (page)
FULL JOIN `project.dataset.table1` one_star USING (page)

您可以使用下面的问题中的虚拟数据进行测试，操作

#standardSQL
WITH `project.dataset.table5` AS (
  SELECT 'A' page, 1 five_star_rating UNION ALL
  SELECT 'B', 1 UNION ALL
  SELECT 'C', 1 
), `project.dataset.table4` AS (
  SELECT 'C' page, 1 four_star_rating UNION ALL
  SELECT 'D', 1 UNION ALL
  SELECT 'F', 1 
), `project.dataset.table3` AS (
  SELECT 'F' page, 1 three_star_rating UNION ALL
  SELECT 'G', 1 UNION ALL
  SELECT 'H', 1 
), `project.dataset.table2` AS (
  SELECT 'H' page, 1 two_star_rating UNION ALL
  SELECT 'I', 1 UNION ALL
  SELECT 'J', 1 
), `project.dataset.table1` AS (
  SELECT 'J' page, 1 one_star_rating UNION ALL
  SELECT 'K', 1 UNION ALL
  SELECT 'L', 1 
)
SELECT
  COALESCE(five_star.page, four_star.page, three_star.page, two_star.page, one_star.page) AS page,
  IFNULL(five_star.five_star_rating, 0) AS five_star,
  IFNULL(four_star.four_star_rating, 0) AS four_star,
  IFNULL(three_star.three_star_rating, 0) AS three_star,
  IFNULL(two_star.two_star_rating, 0) AS two_star,
  IFNULL(one_star.one_star_rating, 0) AS one_star
FROM `project.dataset.table5` five_star
FULL JOIN `project.dataset.table4` four_star USING (page)
FULL JOIN `project.dataset.table3` three_star USING (page)
FULL JOIN `project.dataset.table2` two_star USING (page)
FULL JOIN `project.dataset.table1` one_star USING (page)

预期结果：

Row page    five_star   four_star   three_star  two_star    one_star     
1   A       1           0           0           0           1    
2   B       1           0           0           0           1    
3   C       1           1           0           0           1    
4   D       0           1           0           0           0    
5   F       0           1           1           0           0    
6   G       0           0           1           0           0    
7   H       0           0           1           1           0    
8   I       0           0           0           1           0    
9   J       0           0           0           1           0

Answer 3

查询中的问题：您只添加了那些具有5星级评分的事件页面。这就是为什么推荐full outer join的原因-它向最左边的表中添加了新行。

我认为在您的情况下，解决方案要容易得多，并且根本不需要连接，因为所有数据都在同一表中。这是平坦且无枢轴的：

#standardSQL
  CREATE TEMPORARY FUNCTION tables_in_range(suffix STRING) AS (suffix BETWEEN '20180601' AND '20180630');

SELECT
  h.page.pagePath AS page,
  h.eventInfo.eventLabel stars,
  COUNT(1) as events
FROM
  `project.dataset.ga_sessions_*` AS t, t.hits AS h
WHERE
  h.eventInfo.eventAction='rating'
  AND h.eventInfo.eventLabel between '1' and '5'
  AND tables_in_range(_TABLE_SUFFIX)
  AND REGEXP_CONTAINS(h.page.pagePath,
    r'/xyz/')
  AND h.type='EVENT'
GROUP BY 1, 2

如果您确实需要像枢轴一样的列，它将看起来像这样：

#standardSQL
  CREATE TEMPORARY FUNCTION tables_in_range(suffix STRING) AS (suffix BETWEEN '20180601' AND '20180630');

SELECT
  h.page.pagePath AS page,
  SUM( IF(h.eventInfo.eventLabel = '1', 1, 0) ) as oneStarEvents,
  SUM( IF(h.eventInfo.eventLabel = '2', 1, 0) ) as twoStarEvents,
  SUM( IF(h.eventInfo.eventLabel = '3', 1, 0) ) as threeStarEvents,
  SUM( IF(h.eventInfo.eventLabel = '4', 1, 0) ) as fourStarEvents,
  SUM( IF(h.eventInfo.eventLabel = '5', 1, 0) ) as fiveStarEvents
FROM
  `project.dataset.ga_sessions_*` AS t, t.hits AS h
WHERE
  h.eventInfo.eventAction='rating'
  AND h.eventInfo.eventLabel between '1' and '5'
  AND tables_in_range(_TABLE_SUFFIX)
  AND REGEXP_CONTAINS(h.page.pagePath,
    r'/xyz/')
  AND h.type='EVENT'
GROUP BY 1

您也可以SUM(IF(condition,1,0))代替COUNT(IF(condition,1,NULL))

hth！

在大查询中联接多个表

3 个答案: