TSQL通过百分比查询将“其他”添加到GROUP

问题描述

|| 我将如何构造一个查询，将某个百分比以下的任何内容归类为“其他”？ 例如：

Select Country,(COUNT(Country)*100 / (Select COUNT(*) From Logs)) as Perc
FROM Logs
Group by Country
HAVING (COUNT(Country)*100 / (Select COUNT(*) From Logs)) > 5
ORDER BY Perc DESC

我如何添加一行“ Other”，使所有内容的总和小于6％？     

解决方法

另一种方法

;WITH Logs(Country) AS
(
SELECT TOP 10 \'UK\' FROM sys.objects UNION ALL
SELECT TOP 10 \'US\' FROM sys.objects UNION ALL
SELECT TOP 1 \'Timbuktu\' FROM sys.objects
),GroupedLogs AS
(
SELECT Country,(COUNT(Country) * 100.0 / (SELECT COUNT(*) FROM Logs)) AS Perc
FROM Logs
GROUP BY Country
)
SELECT CASE WHEN Perc<6 THEN \'Other\' ELSE Country END AS Country,SUM(Perc) AS Perc
FROM GroupedLogs
GROUP BY CASE WHEN Perc<6 THEN \'Other\' ELSE Country END

    ,我认为您需要一个UNION。未经测试，但类似：

SELECT * FROM 
(
    Select 
        Country,(COUNT(Country)*100 / (Select COUNT(*) From Logs)) as Perc 
    FROM 
        Logs 
    Group by 
        Country 
    HAVING 
        (COUNT(Country)*100 / (Select COUNT(*) From Logs)) >= 6    

    UNION

    Select 
        \'Other\' as Country,(COUNT(Country)*100 / (Select COUNT(*) From Logs)) as Perc 
    FROM 
        Logs 
    HAVING 
        (COUNT(Country)*100 / (Select COUNT(*) From Logs)) < 6 
)
ORDER BY 
    Perc DESC

    ,或尝试以下方法。此处的百分比是按CTE计算的：

DECLARE @countries TABLE (name varchar(16),hit INT);


INSERT INTO @countries
VALUES
(\'UK\',1),(\'UK\',(\'FRA\',(\'USA\',(\'MEX\',1);

WITH MY_PERCENTAGES AS
(
    SELECT name,CAST(count(*) AS NUMERIC(5,2)) 
                / 
                CAST(SUM(count(*)) OVER() AS NUMERIC(5,2)) * 100.
             AS percentage
    FROM @countries
    GROUP BY name
)
SELECT
    name,SUM (percentage) AS percentages
FROM 
(
    SELECT 
        CASE 
        WHEN percentage <6 THEN
            \'OTHER\'
        ELSE
            name
        END AS name,percentage
    FROM MY_PERCENTAGES
) TMP
GROUP BY name;