4

可以说我有下表:

Student      Course           University
1             a                   x
1             b                   x
1             c                   x
1             a                   y
2             a                   x
2             a                   y
2             a                   z
3             a                   x

对于每个学生,我试图找出他们注册的独特课程和大学的数量。

输出如下:

Student     No. of Courses        No. of Universities
 1             3                         2
 2             1                         3
 3             1                         1

我将如何为此构建 SQL?

4

1 回答 1

12
SELECT Student,
       COUNT(DISTINCT Course)     AS NumberOfCourses,
       COUNT(DISTINCT University) AS NumberOfUniversities
FROM   YourTable
GROUP  BY Student 
于 2013-01-09T21:46:03.407 回答