窗口函数中的基本分组

Question

我第一次使用窗口函数。我有一个基本的窗口函数，我想将结果按介质分组，当我这样做时，我得到了错误：

Error: SELECT list expression references totals.visits which is neither grouped nor aggregated at [1:12]

在我看来，我已经在第一行总结了totals.visits，我在这里遗漏了什么？我希望看到按国家分列的访问总数，例如：

VISITS          COUNTRY
1500            United Kingdom
750             Ireland
etc.

以下是我的疑问：

 SELECT
        SUM(totals.visits) OVER(PARTITION BY geoNetwork.country
                                ORDER BY geoNetwork.country) AS Visits_by_Medium,
        trafficSource.medium AS Medium
    FROM `xxx.ga_sessions_20171010`
    GROUP BY Medium

Answer 1

我认为您只需要一个简单的GROUP BY查询：

SELECT
    SUM(totals.visits) AS VISITS,
    geoNetwork.country
FROM xxx.ga_sessions_20171010
GROUP BY
    geoNetwork.country;

编辑：

运行以下查询，查看作为窗口函数的sum将返回什么：

SELECT
    SUM(totals.visits) OVER(PARTITION BY geoNetwork.country
                            ORDER BY geoNetwork.country) AS Visits_by_Medium,
    trafficSource.medium AS Medium
FROM xxx.ga_sessions_20171010;