SQL Online Quiz

Q 1 - Consider the following schema −

STUDENTS(student_code, first_name, last_name, email, 
         phone_no, date_of_birth, honours_subject, percentage_of_marks);

Which of the following query would display the distinct honours subjects in the STUDENTS table?

A - select honours_subject from students;

B - select distinct honours_subject from students;

C - select all honours_subject from students;

D - select * from students;

Q 2 - What is returned by ROUND(789.8389, 2)?

A - 789.84

B - 789.83

C - 78

D - 789.00

Q 3 - Consider the following schema −

HONOURS_SUBJECT(subject_code, subject_name, department_head);

LOCATIONS(subject_code, department_name, location_id, city);

Select the right query for retrieving records from the tables HONOURS_SUBJECT and LOCATIONS with the USING clause

A - select h.subject_name, l.department_name, h.department_head, l.city from honours_subject h join location l using(subject_code);

B - select h.subject_name, l.department_name, h.department_head, l.city from honours_subject h natural join location l using(subject_code);

C - select h.subject_name, l.department_name, h.department_head, l.city from honours_subject h, location l using(subject_code);

D - None of the above.

Q 4 - Which of the following is not true about SQL joins?

A - An inner join is a join of two tables returning only matching rows.

B - A left or right outer join returns the results of the inner join as well as the unmatched rows in the left or right table respectively.

C - A full outer join returns results of an inner join as well as the results of a left and right join.

D - None of the above.

Q 5 - You want to calculate the minimum percentage of marks obtained under each honours group students, where the minimum marks is more than the minimum marks in economics department. Under which clause should the subquery be?

A - WHERE clause

B - FROM clause

C - HAVING clause

D - None of the above.

Q 6 - Which of the following is true about modifying rows in a table?

A - You can update some rows in a table based on values from another table.

B - If you try to update a record related to an integrity constraint, it raises an error.

C - You can modify multiple columns.

D - All of the above.

Q 7 - Which of the following is not true about the database objects?

A - Indexes improve performance of queries.

B - Views give alternative names to objects.

C - Sequences are numeric value generators.

D - Tables are the basic unit of storage.

Q 8 - Which of the following code will remove all the rows from the table LOCATIONS?

A - DROP TABLE locations;

B - DELETE TABLE locations;

C - TRUNCATE TABLE locations;

D - None of the above.

Q 9 - Which of the following is not true about the Pseudocolumns that return the sequence values?

A - NEXTVAL returns the next available sequence value.

B - CURRVAL gets the current sequence value.

C - PREVVAL gets the previous sequence value.

D - None of the above.

Q 10 - Which of the following statements allows William to change his database user account password to bill?

A - create user william identified by bill;

B - alter user william identified by bill

C - create user william password bill;

D - alter user william password bill;