通过查询从组中获取百分比

Question

我的SQL有问题。我创建了这个查询：

我不知道如何得到一个查询的结果。我知道要计算百分比，我必须将柜台中获得的价值乘以100，然后除以整个计数的总和。你可以帮我吗？

非常感谢。

Answer 1

我认为最简单的方法是使用一个变量：

SELECT browser, counter, counter/@sum 
FROM (SELECT browser, count(*) as counter, (@sum := @sum + count(*)) 
     FROM analyticsCbVisits v INNER JOIN 
      analyticsCbPlatformsBrowsers pb 
      ON v.idChatBotTrackOperation = pb.idChatBotTrackOperation INNER JOIN 
      analyticsBrowsers b 
      ON pb.browser_id = b.id CROSS JOIN 
      (SELECT @sum := 0) params 
     WHERE b.idChatBotTrackOperation = 33 
     GROUP BY browser 
    ) x 

在其他的数据库中，这是简单，因为你可以使用窗口功能。

Answer 2

试试这个：

set @csum := 0; 
SELECT browser,counter,CONCAT(FORMAT(IF(total=0,0,(counter*100.0)/total),2),'%') as percentage FROM(
SELECT browser, count(*) as counter,@csum := @csum+count(*) as total 
FROM analyticsCbVisits 
INNER JOIN analyticsCbPlatformsBrowsers ON analyticsCbVisits.idChatBotTrackOperation = analyticsCbPlatformsBrowsers.idChatBotTrackOperation 
INNER JOIN analyticsBrowsers ON analyticsCbPlatformsBrowsers.browser_id = analyticsBrowsers.id 
WHERE analyticsCbVisits.idChatBotTrackOperation = 33 
GROUP BY browser) t 

另一种方式来解决这个问题：

SELECT browser,counter,CONCAT(FORMAT(IF(total=0,0,(counter*100.0)/total),2),'%') as percentage FROM(
    SELECT browser, count(*) as counter,(SELECT count(*) 
    FROM analyticsCbVisits 
    INNER JOIN analyticsCbPlatformsBrowsers ON analyticsCbVisits.idChatBotTrackOperation = analyticsCbPlatformsBrowsers.idChatBotTrackOperation 
    INNER JOIN analyticsBrowsers ON analyticsCbPlatformsBrowsers.browser_id = analyticsBrowsers.id 
    WHERE analyticsCbVisits.idChatBotTrackOperation = 33) as total 
    FROM analyticsCbVisits 
    INNER JOIN analyticsCbPlatformsBrowsers ON analyticsCbVisits.idChatBotTrackOperation = analyticsCbPlatformsBrowsers.idChatBotTrackOperation 
    INNER JOIN analyticsBrowsers ON analyticsCbPlatformsBrowsers.browser_id = analyticsBrowsers.id 
    WHERE analyticsCbVisits.idChatBotTrackOperation = 33 
    GROUP BY browser) t 

Answer 3

SELECT Table1.Browser, Table1.Counter, Round((Table1.Counter/(Select sum(Table1.Counter) from Table1))*100,2) & " %" AS Percentage 
FROM Table1; 

这个查询在Access完美的作品。它也应该在SQL中。试试看

Answer 4

我会用WITH ROLLUP获得总计数

| Browser | Counter | 
    --------------------- 
    | Firefox | 2 | 
    | Chrome | 1 | 
    | NULL | 3 | 

和计算应用侧的百分数。

但是 - 如果你只是想运行查询和导出的结果，你可以保存总数到一个会话变量在子查询中，并在外部使用它选择：

SELECT browser, counter, 100 * counter/@total as percentage 
FROM (
    SELECT browser, 
     CASE WHEN browser IS NULL 
      THEN @total := COUNT(*) 
      ELSE COUNT(*) 
     END AS counter 
    FROM analyticsCbVisits 
    INNER JOIN analyticsCbPlatformsBrowsers ON analyticsCbVisits.idChatBotTrackOperation = analyticsCbPlatformsBrowsers.idChatBotTrackOperation 
    INNER JOIN analyticsBrowsers ON analyticsCbPlatformsBrowsers.browser_id = analyticsBrowsers.id 
    WHERE analyticsCbVisits.idChatBotTrackOperation = 33 
    GROUP BY browser 
) t 
WHERE browser IS NOT NULL 

这里是一个简体演示：http://rextester.com/QAT75385