Consider the following schema:
Offerings(Course, Semester)
Enrollment(StudId,Course,Semester)
Write a statement level trigger, which removes courses from Offerings for all those courses
whose enrollment falls below 10 students.
Solution:
CREATE TRIGGER WatchEnrollment
AFTER DELETE, INSERT, UPDATE ON Transcript
FOR EACH STATEMENT
DELETE FROM Offerings
WHERE EXISTS
( SELECT E.Course, E.Semester
FROM Enrollment E
WHERE E.Course = Course AND E.Semester = Semester
GROUP BY E.Course, E.Semester
HAVING count(E.StudId) < 10 )
Computer Science & Information Technology
You might also like to view...
A _____ line under a heading indicates subordinate text that is not displayed.
A. green B. blue C. gray D. red
Computer Science & Information Technology
After installation, how many days do you have to activate Windows 7?
A. 7 B. 30 C. 45 D. 60
Computer Science & Information Technology
To Display the Blank Form Tool, you click the Blank Form button in the:
A) Forms group on the Design tab. B) Forms group on the Create tab. C) Tools group on the Create tab. D) Tools group on the Design tab.
Computer Science & Information Technology
Detail sheets display and summarize totals from other worksheets
Indicate whether the statement is true or false
Computer Science & Information Technology