只允许作为顶级合取的 SubQuery 表达式

Question

我想更改现有查询并收到以下错误：

不支持的子查询表达式“已删除”：仅允许作为顶级合取的子查询表达式

现有查询是：

SELECT DISTINCT
    *
FROM
    geoposition_import AS geo
-- do not take into account data for deleted users
WHERE 
    EXISTS (
        SELECT 1 
        FROM geoposition_import_users AS u 
        WHERE u.id = geo.userId 
            AND NOT u.deleted 
    );

在我们更改之后，geoposition_import 中的 userId 可以为空，因为现在机器也可以创建地理位置。所以我将查询更改为

SELECT DISTINCT
    *
FROM
    geoposition_import AS geo
-- do not take into account data for deleted users
WHERE 
    geo.userId IS NULL -- data from non users (e.g. machines) is still fine
    OR
    EXISTS (
        SELECT 1 
        FROM geoposition_import_users AS u 
        WHERE u.id = geo.userId 
            AND NOT u.deleted 
    );

得到了上面提到的错误。

我用谷歌搜索并找到了限制：https://docs.cloudera.com/HDPDocuments/HDP3/HDP-3.1.5/using-hiveql/content/hive_hive_subquery_limitations.html

所以我的猜测是：OR 是问题所在。

现在我的问题：

1. 为什么错误消息表明“删除”是问题所在？
2. 如何重写查询以使其正常工作？

我想到的唯一解决方案是：将条件拆分为单独的视图，然后执行UNION ALL。

喜欢：

CREATE VIEW IF NOT EXISTS geoposition_import_from_non_users AS
SELECT DISTINCT
    *
FROM
    geoposition_import AS geo
WHERE 
    geo.userId IS NULL;

CREATE VIEW IF NOT EXISTS geoposition_import_from_users AS
SELECT DISTINCT
    *
FROM
    geoposition_import AS geo
-- do not take into account data for deleted users
WHERE 
    EXISTS (
        SELECT 1 
        FROM geoposition_import_users AS u 
        WHERE u.id = geo.userId 
            AND NOT u.deleted 
    );

-- staged data with possible duplicates removed
CREATE VIEW IF NOT EXISTS geoposition_import_distinct AS
SELECT * FROM geoposition_import_from_non_users
UNION ALL
SELECT * FROM geoposition_import_from_users;

有没有cmets？

Answer 1

尝试 LEFT JOIN 而不是 EXISTS：

 SELECT DISTINCT
    geo.*
FROM geoposition_import geo
     LEFT JOIN geoposition_import_users u ON u.id=geo.userId AND NOT u.deleted     
WHERE 
    geo.userId IS NULL -- data from non users (e.g. machines) is still fine
    OR u.id IS NOT NULL;