Question

我有三张表喜欢

学生：Sid，SName，SEmail

费用_类型：Fid，FName，FPrice

StudentFees ：Sid（来自学生的 FK ），Fid（来自Fees_Type 的 FK），FDate

每个表的数据：

Student : SID |SName | SEmail 1 | ABC | ABC@www.com 2 | XYZ | xyz@www.com Fees_Type: Fid | FName | FPrice 1 | Chess | 100 2 | Cricket | 200 StudentFees: Sid | Fid| FDate 1 | 1 | 5/2 1 | 2 | 6/2 2 | 1 | 7/2 2 | 2 | 8/2 1 | 1 | 6/2

现在我想获取数据

SID|SName|SEmail | Total_Chess_Played|Total_Cricket_Played | ToTal_Fees 1 | ABC |ABC@www.com | 2 | 1 | 400 2 | XYZ |xyz@www.com | 1 | 1 | 300

我已尝试过以下查询，但无法获得分组依据或完美结果

SELECT s.sId, SEmail, SName, FName ,FPrice FROM Student s INNER JOIN StudentFees sf ON s.sId = sf.EId INNER JOIN Fees_Type f ON f.fId = sf.fId WHERE MONTH(pr.TDDate) = MONTH(dateadd(dd, 1, GetDate())) AND YEAR(pr.TDDate) = YEAR(dateadd(dd, -1, GetDate()))

我是SQL新手。所以请帮助我。

谢谢。

Answer 1

你可以这样做：

SELECT
    Student.SID,
    Student.SName,
    Student.SEmail,
    SUM(CASE WHEN Fees_Type.FName='Chess' THEN 1 ELSE 0 END) AS Total_Chess_Played,
    SUM(CASE WHEN Fees_Type.FName='Cricket' THEN 1 ELSE 0 END) AS Total_Cricket_Played,
    SUM(Fees_Type.FPrice) AS ToTal_Fees
FROM
    Student 
    JOIN StudentFees ON Student.sId = StudentFees.EId
    JOIN Fees_Type ON Fees_Type.fId = StudentFees.fId
WHERE 
    MONTH(StudentFees.TDDate) = MONTH(dateadd(dd, 1, GetDate())) AND
    YEAR(StudentFees.TDDate) = YEAR(dateadd(dd, -1, GetDate())) 
GROUP BY
    Student.SID,
    Student.SName,
    Student.SEmail

Answer 2

试试这个

SELECT
    s.SID,
    s.SName,
    s.SEmail,
    SUM(CASE WHEN ft.FName='Chess' THEN 1 ELSE 0 END) AS Total_Chess_Played,
    SUM(CASE WHEN ft.FName='Cricket' THEN 1 ELSE 0 END) AS Total_Cricket_Played,
    SUM(ft.FPrice) AS ToTal_Fees
FROM
    Student s
    JOIN StudentFees sf ON s.sId = sf.Sid
    JOIN Fees_Type ft ON ft.fId = sf.fId
GROUP BY
    s.SID,
    s.SName,
    s.SEmail

从sql中的三个表中选择数据

2 个答案: