用于计算计算的 SQL Server 2012 查询

Question

我正在 SQL Server 中构建一个查询，用于计算我们收到的调查分数。我们有一个名为overall_score 的列，用户在其中输入一个1-5 的数字作为评分。我正在尝试创建一个存储过程，该过程将根据分数计算评级。

Score rating = (Total count of scores 4 and 5)/(Total number of responses) * 100

我有三个单独的选择语句来创建我需要的结果，但是当我将它们组合在一起时，我的输出为 0。

有人可以指导我在这里做错了什么吗？

单独的 SQL 语句：

SELECT count(overall_score) FROM Layer1_DataMerge WHERE overall_score = 4;  
SELECT count(overall_score) FROM Layer1_DataMerge WHERE overall_score = 5;  
SELECT count(overall_score) FROM Layer1_DataMerge;  

结合在一起：

SELECT distinct
(  
    (
        (SELECT count(overall_score) FROM Layer1_DataMerge WHERE Overall_Score = 4) +  
        (SELECT count(overall_score) FROM Layer1_DataMerge WHERE overall_score = 5)
    ) / (SELECT count(overall_score) FROM Layer1_DataMerge)
) AS CSAT  
FROM Layer1_DataMerge;

Answer 1

你得到零的原因是因为你正在做整数除法。整数除法 1/3 = 0。您需要转换为浮点运算，而且您可以在一个查询中完成所有操作：

SELECT 100.0 * 
       (SUM(CASE WHEN overall_score = 4 THEN 1 ELSE 0 END) + 
       SUM(CASE WHEN overall_score = 5 THEN 1 ELSE 0 END)) / 
       COUNT(overall_score)

或

SELECT 100.0 * 
       SUM(CASE WHEN overall_score IN (4,5) THEN 1 ELSE 0 END) / 
       COUNT(overall_score)

要仅显示 2 位小数，您可以转换为具有 2 位小数的数字类型：

SELECT CAST(
         100.0 * 
         SUM(CASE WHEN overall_score IN (4,5) THEN 1 ELSE 0 END) / 
         COUNT(overall_score)
       AS NUMERIC(5,2))

或者使用STR转换成字符串：

SELECT STR(
         100.0 * 
         SUM(CASE WHEN overall_score IN (4,5) THEN 1 ELSE 0 END) / 
         COUNT(overall_score)
       ,5,2)