Question

我在sql（以及任何类型的编码）中完成了新手，但是我试图编写一个基本查询，按国家/地区返回首次登录的用户数量8月15日之后，以及第一次会议后第二天回来的用户数量。

我正在处理一个名为events的表，其中包含以下列： utc_timestamp，name，id和包含此事件的几个参数的json字符串（如您所见，我用它来检索会话号和国家/地区）

当我运行此查询时，它会说＆＃34;第5行：无法识别＆＃39; SELECT＆＃39;附近的输入。＆＃39; DISTINCT＆＃39; ＆＃39; ID＆＃39;在功能规范＆＃34;。我尝试在select和DISTINCT之间放置括号，我仍然会收到相同的错误消息。是什么导致它的想法？

感谢您的帮助

SELECT 
get_json_object(json, '$. User_Country ') AS country
, COUNT(DISTINCT id) AS Users
, COUNT(
    SELECT DISTINCT id 
    FROM events 
    WHERE EXISTS(
        SELECT * 
        FROM events
        WHERE name = "Logged_in" 
        AND utc_timestamp>(
            (
            SELECT utc_timestamp
            FROM events
            WHERE month = 201408
            AND name = "Logged_in" 
            AND get_json_object(json, '$. Session_nb ') = 0
            AND utc_timestamp > UNIXTIMESTAMP('2014-08-15 12:00:00')
            ) + INTERVAL '1 day'
        )
    )
) AS Retained1
FROM events 
WHERE month = 201408 
AND name = "Logged_in" 
AND get_json_object(json, '$. Session_nb ') = 0
AND utc_timestamp > UNIXTIMESTAMP('2014-08-15 12:00:00')
GROUP BY (get_json_object(json, '$. User_Country ')) 
ORDER BY (get_json_object(json, '$. User_Country '))

Answer 1

不计算子查询结果。相反，在子查询本身中使用COUNT。

SELECT 
get_json_object(json, '$. User_Country ') AS country
, COUNT(DISTINCT id) AS Users
, (
    SELECT COUNT(DISTINCT id)
    FROM events 
    WHERE EXISTS(
        SELECT * 
        FROM events
        WHERE name = "Logged_in" 
        AND utc_timestamp>(
            (
            SELECT utc_timestamp
            FROM events
            WHERE month = 201408
            AND name = "Logged_in" 
            AND get_json_object(json, '$. Session_nb ') = 0
            AND utc_timestamp > UNIXTIMESTAMP('2014-08-15 12:00:00')
            ) + INTERVAL '1 day'
        )
    )
) AS Retained1
FROM events 
WHERE month = 201408 
AND name = "Logged_in" 
AND get_json_object(json, '$. Session_nb ') = 0
AND utc_timestamp > UNIXTIMESTAMP('2014-08-15 12:00:00')
GROUP BY (get_json_object(json, '$. User_Country ')) 
ORDER BY (get_json_object(json, '$. User_Country '))

SQL保留查询

1 个答案: