Question

我有这个查询在我的网站上显示趋势（搜索次数最多）的名单：

SELECT name, COUNT(*) AS total_trends
FROM trending_names
WHERE dateTime BETWEEN '"&fromDate&"' AND '"&toDate&"' // -7 days to Now()
GROUP BY name
ORDER BY COUNT(*) DESC
LIMIT 10;

...这就是我打印到屏幕的结果：（数字代表搜索量）

Angelina Jolie        31,293
Rihanna               26,722
Lindsay Lohan         18,351
Brad Pitt             11,901

我现在想将数字改为百分比;所以我真的需要在过去7天内获得所有趋势名称的总数，以计算正确的百分比。

我是否可以在不添加其他查询的情况下为此查询添加总计数？

Answer 1

您可以在单个查询中执行：

尝试下面的内容：

SELECT name, COUNT(*) AS total_trends,
sum(if(dateTime BETWEEN '"&fromDate&"' AND '"&toDate&"' ,1,0)) as total_last_7_days,
((sum(if(dateTime BETWEEN '"&fromDate&"' AND '"&toDate&"' ,1,0)) /COUNT(*) ) *100)
as percentage                          // if you want to get only percentage
FROM trending_names
GROUP BY name
ORDER BY COUNT(*) DESC
LIMIT 10;

Answer 2

您可以使用子查询：

SELECT name, ((COUNT(*)*100)/(SELECT COUNT(*) FROM trending_names))  AS total_trends
FROM trending_names
WHERE dateTime BETWEEN '"&fromDate&"' AND '"&toDate&"' // -7 days to Now()
GROUP BY name
ORDER BY COUNT(*) DESC
LIMIT 10;

Answer 3

我知道你没有运行SQL Server，但有些读者可能会对这种可能的紧凑型解决方案感兴趣（SQL Server 2008或更高版本）。我不确定很多人都知道你可以有一个聚合聚合的窗口聚合。

select
  name,
  100.0*count(*)/sum(count(*)) over () as pct_trends
from trending_names
where dateTime between getdate()-7 and getdate()
group by name;

Answer 4

不，我不这么认为。您需要在单独的（子）选择

上计算总计数

Answer 5

SELECT name,(total_trends*100.0/sum_total_trends) pct_trends
FROM
(
    SELECT name, COUNT(*) AS total_trends 
    FROM trending_names 
    WHERE dateTime BETWEEN '"&fromDate&"' AND '"&toDate&"' // -7 days to Now() 
    GROUP BY name 
    WITH ROLLUP
) A,
(
    SELECT COUNT(*) AS sum_total_trends 
    FROM trending_names 
    WHERE dateTime BETWEEN '"&fromDate&"' AND '"&toDate&"' // -7 days to Now() 
) B;

SQL - 为select子句添加计数

5 个答案: