Question

我加入了两个数据表。

Student 
UPN | Name

和

Subject
UPN | Subject | Result

我编写了以下查询以显示所有值的列表。

SELECT student.upn,
       subject,
       result
FROM   student
       JOIN subject
         ON subject.upn = student.upn

这导致以下

UPN             Subject       Result
8152760         English       3c
8138130         Spanish       2b
8152760         Spanish       3c
8128500         English       3c
8152760         Mathematics   2b
8152760         French        2b

我想要做的是让每个不同学生的结果集显示为每个主题的列，如下所示：

UPN             English      French      Mathematics      Spanish
8152760         3c           2b          2b               3c
8138130         NULL         NULL        NULL             2b
8128500         3c           NULL        NULL             NULL

理想情况下，我希望自动生成主题名称中的列，但如果这更直接，我很乐意对它们进行硬编码。

Answer 1

你走了：

declare @t as table (UPN int, Subject varchar(50), Result varchar(3))
insert into @t values(8152760, 'English'     ,  '3c')
insert into @t values(8138130, 'Spanish'     ,  '2b')
insert into @t values(8152760, 'Spanish'     ,  '3c')
insert into @t values(8128500, 'English'     ,  '3c')
insert into @t values(8152760, 'Mathematics' ,  '2b')
insert into @t values(8152760, 'French'      ,  '2b')



select distinct t.upn, 
e.Result as Enlish,
s.Result as Spanish,
f.Result as French,
m.Result as Mathematics
from @t t
left join @t e on e.UPN = t.upn and e.Subject = 'English'
left join @t s on s.UPN = t.upn and s.Subject = 'Spanish'
left join @t f on f.UPN = t.upn and f.Subject = 'French'
left join @t m on m.UPN = t.upn and m.Subject = 'Mathematics'

PIVOT版仅适用于聚合，这就是我删除评论的原因）

SELECT UPN, 
[English]        ,
[Spanish]        ,                       
[Mathematics]    ,
[French]
FROM
(SELECT UPN, Subject, Result 
    FROM @t) AS SourceTable
PIVOT
(
count(Result)
FOR Subject IN ([English]        ,
                [Spanish]        ,                       
                [Mathematics]    ,
                [French])
) AS PivotTable;

SQL结果从List设置为网格

1 个答案: