设计表
4.按专业统计课程数量:
sql
SELECT Major, COUNT(*) AS Num
FROM Course
GROUP BY Major
5.按专业查询所有课程信息:
sql
SELECT * FROM Course WHERE Major = '信息技术'
6.统计“信息技术”专业的课程数量:
sql
SELECT COUNT(*) FROM Course WHERE Major = '信息技术'
7.按学分将“信息技术”专业的课程排序:
sql
SELECT * FROM Course WHERE Major = '信息技术'
ORDER BY Credit DESC
8.统计“信息技术”专业课程的平均学时:
sql
SELECT AVG(Period) AS AvgPeriod
FROM Course
WHERE Major = '信息技术'
9.查询“信息技术”专业,学时最长的课程信息:
sql
SELECT * FROM Course
WHERE Major = '信息技术' AND Period = (
SELECT MAX(Period) FROM Course WHERE Major = '信息技术'
)