SQLFiddle

Question

如何转置此表，以便我有两列，一列显示付费用户的比率，一列显示免费用户的比率。另外，在我的脚本中，有任何方法可以使代码更简洁，并且SQL＆＃39;喜欢？我似乎无法在sqlfiddle中使用select语句创建表，因为我收到一条错误，说它只能在架构屏幕中创建。无论如何我可以将sql语句嵌入到新表中吗？

我在sqlfiddle上创建了一个脚本，可以为不同类型的用户计算一些下载指标：http://sqlfiddle.com/#!9/79bea4/1

Answer 1

SELECT df.Date,
       SUM(CASE WHEN ad.paying_customer = 'No'
                THEN df.downloads ELSE 0 END) /
       SUM(CASE WHEN ad.paying_customer = 'No' THEN 1 ELSE 0 END) AS `Average Downloads/Free User`,
       SUM(CASE WHEN ad.paying_customer = 'Yes'
                THEN df.downloads ELSE 0 END) /
       SUM(CASE WHEN ad.paying_customer = 'Yes' THEN 1 ELSE 0 END) AS `Average Downloads/Paid User`
FROM
(
    SELECT date,
           user_id,
           SUM(downloads) AS downloads
    FROM download_facts
    GROUP BY date,
             user_id
) df
INNER JOIN user_dimension ud
    ON df.user_id = ud.user_id
INNER JOIN account_dimension ad
    ON ud.account_id = ad.account_id
GROUP BY df.Date

在这里演示：

SQLFiddle

Answer 2

您可以通过获取下载总和并除以用户数来计算平均值。然后count(distinct)可以获得每个组中的用户：

select df.date,
       (sum(df.downloads) /
        count(distinct case when ad.paying_customer = 'No' then df.user_id end)
       ) as avg_free,   
       (sum(df.downloads) /
        count(distinct case when ad.paying_customer = 'Yes' then df.user_id end)
       ) as avg_paying   
from download_facts df left join
     user_dimension ud
     on df.user_id = ud.user_id left join
     account_dimension ad
     on ad.account_id = ud.account_id
group by df.date;

转换SQL表的最简洁方法

2 个答案:

SQLFiddle