大连理工大学软件学院——数据库上机题3

大连理工大学软件学院——数据库上机题3

Using the university schema that you have write the following queries. In some cases you

might need to insert extra data to show the effect of a particular feature.

1. Insert each student as an instructor of department ‘拳脚学院’, with salary=40000

2. Now delete all the newly added "instructors" above (note: already existing instructors who happened to have salary=40000 should not get deleted)

3. Update the salary of each instructor to 10000 times the number of course sections they have taught.

4. The university rules allow an F grade to be overridden by any pass grade (for example, A).

Now, lists students who have fail grades that have not been overridden. For each student as such, information displayed (in one row) should involve:

l Identifier of student

l Name of student

l Count of F grades that have not been overridden.

5. In one result, list the instructors who have never taught any courses and the students who have never registered for any courses. For each person, information displayed (in one row) should involve:

l Id of the person

l Name of the person

l Role of the person. The value of role should be ‘student’ or ‘instructor’.

insert into  instructorselect S.id,S.name,'拳脚学院',40000from student as Swhere S.id not in (select instructor.id from instructor) delete from instructorwhere name+id in (select name+id from student) sp_help instructorsp_helpconstraint instructoralter table instructordrop constraint CK__instructo__salar__1920BF5Cupdate instructorset salary= 10000*(select COUNT(*) from teaches where instructor.id=teaches.id) with S(id,course_id) as (select distinct id,course_id from takes where grade='F'),R(id,course_id) as (select distinct T.id,T.course_idfrom takes as T,Swhere T.id=S.id and T.course_id=S.course_idand T.grade<>'F' )select student.ID,student.name,count(*) as FailedTimesfrom (select * from S except select *from R) as target,studentwhere target.id=student.idgroup by student.ID,student.name select S.id,S.name,'Student' as Rolefrom Student as Swhere S.id not in(select takes.id from takes)unionselect T.id,T.name,'Instructor' as Rolefrom instructor as Twhere T.id not in (select teaches.id from teaches)