按组连接

Question

我有针对学生的下表：

+----------+-------+-----+
|StudentID |Subject|Score|
+----------+-------+-----+
|1011010   |Phy    |54   |
+----------+-------+-----+
|1011020   |Phy    |78   |
+----------+-------+-----+
|1011010   |Maths  |76   |
+----------+-------+-----+
|1011030   |Maths  |65   |
+----------+-------+-----+

如何将结果显示为针对每个学生的单个连接字符串？ 因此，在上面的数据中我应该返回以下内容：

+---------+---------------+
|StudentID|Result         |
+---------+---------------+
|1011010  |Phy-54,Maths-76|
+---------+---------------+
|1011020  |Phy-78,Maths-65|
+---------+---------------+

我正在使用Sql server 2008。

Answer 1

试试这个

SELECT StudentID,
       ( SELECT Subject + '-' + Score + ','
           FROM students t2
          WHERE t2.StudentID = t1.StudentID
          ORDER BY Name
            FOR XML PATH('') ) AS Name
      FROM students t1
      GROUP BY StudentID ;

Answer 2

Stuff()应该这样做：

select t1.StudentID,
  STUFF(
       (SELECT ', ' + t2.Subject+ '-' + cast([Score] as varchar)
        FROM Students t2
        where t1.StudentID = t2.StudentID
        FOR XML PATH (''))
        , 1, 1, '')  AS Grades
from Students t1
group by studentID