如果没有明确使用ISNULL，则左连接失败

I have a large table User and a small table User_purchase in google bigquery.

我有一个大表用户和google bigquery中的小表User_purchase。

If I join the two with

如果我加入两个

SELECT User.id, User_purchase.amount FROM User 
    LEFT JOIN User_purchase on User.id = User_purchase.user_id,

the query returns error:

查询返回错误：

Query Failed. Error: Not Implemented: This table cannot be read

查询失败。错误：未实现：无法读取此表

But if I join the two with

但如果我加入这两个

SELECT User.id, ISNULL(INTEGER(User_purchase.amount), INTEGER(0)) FROM User 
    LEFT JOIN User_purchase on User.id = User_purchase.user_id,

the query works.

查询有效。

Don't quite understand why the first case does not work. I assume in the first case I can get all users with their purchase_amount though some users will have NULL as their purchase_amount. Thanks.

不太明白为什么第一种情况不起作用。我假设在第一种情况下我可以使用purchase_amount获得所有用户，尽管有些用户将使用NULL作为purchase_amount。谢谢。

1 个解决方案

#1

This is a bug relating to nested field names in query replies. I've got a fix for the bug but it won't go out until next week's release. Thanks for bringing it to our attention.

这是与查询回复中的嵌套字段名称相关的错误。我已经修复了这个bug，但是在下周发布之前它不会发布。感谢您引起我们的注意。

1 个解决方案

#1

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