The Binary BrothersTwo Mentors, One Mission – Your Selection
All mock tests are FREE till 31 December — register to save your progress
Unit 4 · Database Management Systems Paper 2 CS · December 2022 (Shift 1)

Directions (Q96–100): Academic database schema: student(rollno, name, degree, year, sex, deptno, advisor); department(deptid, name, hod, phone); professor(empid, name, sex, startyear, deptno, phone); course(courseid, cname, credits, deptno); enrollment(rollno, courseid, sem, year, grade); teaching(empid, courseid, sem, year, classroom); prerequisite(precourseid, courseid). deptno in student, professor and course refers to department.deptid; advisor refers to professor.empid; hod refers to professor.empid; enrollment.rollno refers to student.rollno; courseid in enrollment and teaching refers to course.courseid; teaching.empid refers to professor.empid; precourseid and courseid in prerequisite refer to course.courseid.

Given query: select s.rollno, s.name from student s where EXISTS (select c.courseid from course c Where c.deptno =5 and EXISTS (select e.* from enrollment e where e.courseid = c.courseid and e.rollno = s.rollno)); Which one of the following statements is correct with respect to the given query?

Pick an option to check yourself, or open the answer below.

Show answer & explanation

Correct answer: C. It retrieves the roll number and names of students who have enrolled for at least one course offered by department number 5

Explanation

The student is returned if there EXISTS some department-5 course for which an enrollment by that student EXISTS, i.e. at least one department-5 course.

More Database Management Systems questions