Multiple choice questions in DBMS, Database management systems introduction concepts solved quiz, solved MCQ in DBMS with answers
Database Management Systems Quiz
1. In ABC University, there are several departments including Computer Science, Information Technology, Mechanical, Civil, Finance and Maintenance. Some departments have students and some are not. If department and student are entity sets in this university database and they are linked through a relationship named DS, which among the following is a partial participation?
a. Participation of department in student
b. Participation of department in DS
c. Participation of student in department
d. Participation of student in DS
Answer:
Option (b)
As per the question, the student must belong to a department whereas there are few departments without students. Hence, the participation of department entity set in the relationship DS is partial participation.
2. ABC Airways uses software to manage reservation of its passengers. After a year of its use, the database administrator decided to add few attributes with the passenger table. If he is able to change the structure of passenger table without adjusting its front-end, how do we call such independence?
a. Physical data independence
b. Logical data independence
c. External data independence
d. View data independence
Answer:
Option (b)
The administrator changes the structure of the table by adding few attributes. Adding a few attributes doesn’t do anything with the existing front-ends (interface). This is the ability to change something in the logical level without affecting the view level and this independence is called as logical data independence.
3. Consider the following ER diagram.
The minimum number of tables needed to represent E1, E2, E3, R1, R2 is
a. 5
b. 4
c. 3
d. 2
Answer:
Option (c)
The relationship R1 is a many-to-one relationship from M to P and R2 is a one-to-many relationship from P to N. Hence, R1 and R2 will not be reduced into separate schemas. Only M, N and P will be created as separate tables.
4. CONCERT and CONDUCTOR are entity sets with attributes as follows;
CONCERT (coid, location, time, date), CONDUCTOR (soloid, fname, lname, phone).
CONDUCTS is a one-to-many relationship from CONDUCTOR to CONCERT. While reducing the ERD to schemas, what would be the schema for CONDUCTS?
a. CONDUCTS(coid, soloid)
b. CONDUCTS(coid, location, time, date, soloid, fname, lname, phone)
c. CONDUCTS(soloid, coid)
d. None of the above
Answer:
Option (d)
Relationship CONDUCTS is a one-to-many relationship. Hence, the primary key attribute of one side entity set (CONDUCTOR) will be included as the foreign key into the many side entity set (CONCERT).
5. Identify the use of the check constraint in the following statement.
CHECK( state IN ( ‘Punjab’, ‘Tamil Nadu’, ‘Goa’))
a. The condition checks whether the attribute includes the three mentioned names
b. The condition allows the attribute to possess only the three mentioned names
c. The condition checks whether the given names are sub-strings in at least one of the values
d. None of the mentioned
Answer:
Option (b)
CHECK constraint in SQL permits to include conditions with the CREATE TABLE statement. The condition which is given in question, make sure that the permitted values for attribute state is either ‘Punjab’, ‘Tamil Nadu’, or ‘Goa’.
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