Big Query 过滤自定义查询创建表的空行

Posted 2023-03-25

【中文标题】Big Query 过滤自定义查询创建表的空行

【英文标题】：Big Query filtering null rows of Custom query creating table

【发布时间】：2019-12-04 07:31:09

【问题描述】：

我正在尝试在大查询中查询我的数据，并希望避免空记录但继续获取它们。

这是我目前的查询：

select 
(SELECT x.value FROM UNNEST(user_properties) x 
WHERE x.key='restaurantName' 
and x.value is not null).string_value as restaurantName ,
(SELECT x.value FROM UNNEST(user_properties) x 
WHERE x.key='restaurantId' and x.value is not null).string_value as 
restaurantID , 
(SELECT x.value FROM UNNEST(user_properties) x 
WHERE x.key='user_id' and x.value is not null).string_value as user 
FROM some_data_set where event_name="ConfirmOrderBtn" and event_date between 
'20191110' and '_*' and app_info.id = "app_id"

这是我的查询结果：

【参考方案1】：

以下是 BigQuery 标准 SQL

#standardSQL
SELECT * FROM (
  SELECT 
    (SELECT x.value 
      FROM UNNEST(user_properties) x 
      WHERE x.key='restaurantName' 
      AND x.value IS NOT NULL
    ).string_value AS restaurantName ,
    (SELECT x.value 
      FROM UNNEST(user_properties) x 
      WHERE x.key='restaurantId' 
      AND x.value IS NOT NULL
    ).string_value AS restaurantID , 
    (SELECT x.value 
      FROM UNNEST(user_properties) x 
      WHERE x.key='user_id' 
      AND x.value IS NOT NULL
     ).string_value AS user 
  FROM `project.dataset.some_data_set` 
  WHERE event_name="ConfirmOrderBtn" 
  AND event_date BETWEEN '20191110' AND '_*' 
  AND app_info.id = "app_id" 
)
WHERE NOT (restaurantName IS NULL OR restaurantID IS NULL OR user IS NULL)

【参考方案2】：

欢迎，添加 WHERE 子句（例如 WHERE restaurant_name IS NOT NULL）将阻止 'restaurant_name' 中具有空值的行出现在您的结果中。

更新：现在我可以看到您的查询非常复杂并且使用子查询 - 如果您想从最终结果中过滤我们的空值，在这种情况下，您可以使用 HAVING ， 例如： HAVING restaurant_name 不为空`

HAVING 在您的子查询之后执行，因此它会链接结果的最终过滤器 - 请注意，您仍需为返回 HAVING 子句之前的所有数据付费。

这是HAVING 上文档的链接： https://cloud.google.com/bigquery/docs/reference/standard-sql/query-syntax#having-clause

希望有帮助！

【讨论】：

以下是我的查询选择 (SELECT x.value FROM UNNEST(user_properties) x WHERE x.key='restaurantName' and x.value is not null).string_value as restaurantName , (SELECT x.value FROM UNNEST(user_properties) x WHERE x.key='restaurantId' and x.value is not null).string_value as restaurantID , (SELECT x.value FROM UNNEST(user_properties) x WHERE x.key='user_id' and x.value不为空).string_value 作为用户 FROM some_data_set 其中 event_name="ConfirmOrderBtn" 和 event_date 介于 '20191110' 和 '_*' 和 app_info.id = "app_id"

感谢您的欢迎 :) 。我还在查询中添加了不为空的检查，但它仍然返回空记录

谢谢，我已编辑您的问题以添加到此查询中并相应地更新了我的答案！