Question

我需要将列值与另一列值相乘，然后找到总和

SubjectTable

SubjectMarksId SubjectCode Marks

1                  4ww      50
2                  8qw      50
3                  7uy      50

MarksType

MarksTypeId MarksType  StudentCount Marks
1            Sports        1        10
2            Math          1        10
3            English       1        1
4            Physics       1        10  // Marks sum(10+10+1*50+10) multiply condition, where  MarksTypeId=3 with SubjectCode = 8qw in SubjectTable

这是我试图成倍增加的方式

select StudentMark*(SELECT  Marks  AS SubjectMark
FROM    SubjectTable
WHERE   SubjectCode = '8qw')
from
(
SELECT  Marks  AS StudentMark
FROM    MarksType
WHERE   MarksTypeId= '3'

) src

最后是总和，它工作正常，但如何乘以另一列值然后找到总和？

SELECT Student.StudentId, Student.Name, sum(MarksType.Marks) as  TotalMarks
FROM
MarksType
INNER JOIN
MarksDetails on MarksType.MarksTypeId = MarksDetails.MarksTypeId
INNER  JOIN 
Student on Student.StudentId =  MarksDetails.StudentId

group by Student.Name,Student.StudentId

任何帮助都会很棒。

     UPDATE:

由于情况原因，表格细节较少，所以输出错误，无论如何感谢@Darka和Piyush。下一次从我这边的细节将以明确的方式提供，如果要求我可以通过版主的帮助删除这个问题。这可能会影响其他人的研究。

Answer 1

你可以在SUM函数中进行数学运算，即

SUM(Column1 * Column2) as Result

Answer 2

你可以这样做：

SELECT SUM(MT.Marks * ISNULL(T.Marks,1))
FROM MarksType AS MT
OUTER APPLY (
                SELECT ST.Marks 
                FROM SubjectTable AS ST 
                WHERE ST.SubjectCode = '8qw' AND MT.MarksTypeId= 3
            ) AS T(Marks)

最后SUM可以是这样的（只是猜测没有提供数据）：

SELECT Student.StudentId, Student.Name, sum(MT.Marks * ISNULL(T.Marks,1)) as  TotalMarks
FROM MarksType AS MT
OUTER APPLY (
                SELECT ST.Marks 
                FROM SubjectTable AS ST 
                WHERE ST.SubjectCode = '8qw' AND MT.MarksTypeId= 3
            ) AS T(Marks)
INNER JOIN MarksDetails 
    on MT.MarksTypeId = MarksDetails.MarksTypeId
INNER JOIN Student 
    on Student.StudentId =  MarksDetails.StudentId
group by Student.Name,Student.StudentId

sql从另一列sum乘以列

2 个答案: