SQL Round Number Over（）

Question

我有一个非常基本的SQL查询查询，它正在对从分组结果集返回的记录总数进行计算。

SELECT vco.OutcomeName, 
      vco.VersionCompareOutcomeID, 
      COUNT(t.OutcomeName) AS Total, 
      ROUND(COUNT(*) * 100.0/sum(count(*)), 1) over() AS Percentage 
FROM map.VersionCompareOutcome AS vco 
LEFT JOIN @temp AS t 
ON vco.VersionCompareOutcomeID = t.VersionCompareOutcomeID 
GROUP BY vco.OutcomeName, vco.VersionCompareOutcomeID 

当我尝试并使用round功能，我收到以下错误：The function 'ROUND' is not a valid windowing function, and cannot be used with the OVER clause.

没有round功能，我得到的百分比，但其不圆像我想要的目的。

我希望的结果是小数点后两位：例如87.95%。

Answer 1

不能使用ROUND与OVER，只有聚集，排名和分析功能可经由使用。

但是，你可以做你聚集在一个子查询或CTE，然后做在外部查询取整：

WITH CTE 
AS 
(

    SELECT vco.OutcomeName, 
       vco.VersionCompareOutcomeID, 
       COUNT(t.OutcomeName) AS Total 
    FROM map.VersionCompareOutcome AS vco 
    LEFT JOIN @temp AS t ON vco.VersionCompareOutcomeID = t.VersionCompareOutcomeID 
    GROUP BY vco.OutcomeName, vco.VersionCompareOutcomeID 
) 
SELECT 
    OutcomeName, 
    VersionCompareOutcomeID, 
    Total, 
    CASE WHEN (SELECT COUNT(*) FROM @temp) = 0 THEN 0 ELSE ROUND(Total * 100.0/(SELECT COUNT(*) FROM @temp), 1) END AS Percentage 
FROM CTE