Question

我有两个表tblStudent和tblTranscript。我想计算拥有GPA＆gt;的学生百分比3.5。我创建了两个查询，这些查询给出了拥有GPA的学生总数和拥有GPA的学生总数> 3.5。

我不知道如何划分这两个表并将它们乘以100以获得具有GPA＆gt;的学生的百分比。 3.5。

我的疑问是：

GPA＆gt; 3.5

SELECT COUNT (GPA) FROM (
SELECT avg(Grade) as GPA, studentID from tblTranscript
GROUP BY studentID HAVING avg(Grade) > 3.5)

TotalCountWithGPA

SELECT COUNT (GPA) FROM (
SELECT avg(Grade) as GPA, StudentID FROM tblTranscript
GROUP BY StudentID)

解决方案：

SELECT

(COUNT (GPA) 
/ 
(SELECT COUNT(GPA) FROM (SELECT avg(Grade) as GPA, StudentID FROM tblTranscript GROUP BY StudentID)) * 100) as PercentageOfStudents

FROM (SELECT avg(Grade) as GPA, studentID from tblTranscript GROUP BY studentID HAVING avg(Grade) > 3.5)

Answer 1

试试这个，

SELECT 
(COUNT (studentID)/(SELECT COUNT(studentID) FROM tblTranscript)) as percentageOfStudents 
FROM (
        SELECT avg(Grade) as GPA, studentID from tblTranscript
        GROUP BY studentID HAVING avg(Grade) > 3.5)

希望它会像你期待的那样工作

Answer 2

我现在明白你的问题。由于找不到页面错误，我无法编辑我的最后一个答案。无论如何，我已经编辑了我的最后一个答案并发布了。检查它是否有效，

SELECT 
(COUNT(GPA)/(SELECT COUNT(GPA) FROM (SELECT avg(Grade) as GPA, studentID from tblTranscript)) * 100) as percentageOfStudents 
FROM (
        SELECT avg(Grade) as GPA, studentID from tblTranscript
        GROUP BY studentID HAVING avg(Grade) > 3.5)

Answer 3

MySQL还是Access？

对于MySQL，您可以使用：

SELECT COUNT(GPA > 3.5)/COUNT(GPA)*100 as HIGH_GPA_PERC
FROM(SELECT avg(Grade) as GPA, StudentID
     FROM tblTranscript
     GROUP BY StudentID) t

如何计算GPA的百分比>从两张桌子3.5？

3 个答案: