SQL用于查找每个用户的计数

时间:2013-01-09 21:43:50

标签: sql count distinct

假设我有下表:

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,我都在努力寻找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

我如何为此构建SQL?

1 个答案:

答案 0 :(得分:10)

SELECT Student,
       COUNT(DISTINCT Course)     AS NumberOfCourses,
       COUNT(DISTINCT University) AS NumberOfUniversities
FROM   YourTable
GROUP  BY Student