sql 脚本适用于 MySQL，但不适用于 google bigquery

Posted 2023-03-25

【中文标题】sql 脚本适用于 MySQL，但不适用于 google bigquery

【英文标题】：sql script works on MySQL, but not on google bigquery

【发布时间】：2013-02-27 20:34:26

【问题描述】：

我有在 mysql 中运行良好的 sql 脚本，但我无法在 google bigquery 中运行。通读 bq 文档后，我做了一些调整（例如，每个 select 语句不超过一个 join），但脚本仍然失败。任何帮助表示赞赏。如果您知道 bq sql 与其他 sql 方面的任何好的资源，那也将不胜感激。谢谢。

SELECT 
T1.action_date AS action_date,
T1.ad_campaign_category AS ad_campaign_category,
T1.campaign_id AS campaign_id,
T2.total_sends AS total_sends, 
count(*) AS clicks_per_category
FROM ( 
    SELECT action_date, campaign_id, ad_campaign_category
    FROM projectX.email_action
    WHERE action_date > '2009-04-01' AND action_date < '2011-05-01') T1,

    (
    SELECT action_date, campaign_id, ad_campaign_category, count(*) AS total_sends
    FROM projectX.email_action
    WHERE action_type = 'send' AND action_date > '2009-04-01' AND action_date < '2011-05-01'
    GROUP BY action_date, campaign_id) T2

WHERE T1.action_date = T2.action_date 
    AND T1.campaign_id = T2.campaign_id
GROUP BY action_date, campaign_id, ad_campaign_category

【问题讨论】：

您是否遇到了特定的错误消息？

下面的答案纠正了这个问题。这是错误消息：错误：未知字段：T1.action_date

【参考方案1】：

JOIN 必须是显式的——也就是说，您应该使用SELECT ... FROM (...) t1 JOIN (...) t2 ON t1.x = t2.y 的形式，而不是使用SELECT ... FROM (...) t1, (...) t2 WHERE t1.x = t2.y 对于您的示例，这看起来像：

SELECT 
T1.action_date AS action_date,
T1.ad_campaign_category AS ad_campaign_category,
T1.campaign_id AS campaign_id,
T2.total_sends AS total_sends, 
count(*) AS clicks_per_category
FROM ( 
    SELECT action_date, campaign_id, ad_campaign_category
    FROM projectX.email_action
    WHERE action_date > '2009-04-01' AND action_date < '2011-05-01') T1
JOIN (
    SELECT action_date, campaign_id, ad_campaign_category, count(*) AS total_sends
    FROM projectX.email_action
    WHERE action_type = 'send' AND action_date > '2009-04-01' AND action_date < '2011-05-01'
    GROUP BY action_date, campaign_id) T2
ON T1.action_date = T2.action_date 
AND T1.campaign_id = T2.campaign_id
GROUP BY action_date, campaign_id, ad_campaign_category

请注意，如果您收到一个表太大的错误，请尝试使用JOIN EACH 而不是JOIN。