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 all the students with honours_subject ‘Eng01’?

A - select student_code, first_name, last_name from students where honours_subject = ‘Eng01’;

B - select student_code, first_name, last_name from students where honours_subject is ‘Eng01’;

C - select student_code, first_name, last_name where honours_subject = ‘Eng01’

    from students;

D - select student_code, first_name, last_name from students;

Q 2 - What is returned by SUBSTR(‘TUTORIALS POINT’, -1, 1)?

A - T

B - NULL

C - 0

D - N

Q 3 - Consider the following schema −

HONOURS_SUBJECT(subject_code, subject_name, department_head);

LOCATIONS(subject_code, department_name, location_id, city);

Which query will perform a natural join between the HONOURS_SUBJECT table and the LOCATIONS table?

A - select subject_code, subject_name, location_id, city from honours_subject cross join locations;

B - select subject_code, subject_name, location_id, city from honours_subject join locations;

C - select subject_code, subject_name, location_id, city from honours_subject outer join locations;

D - select subject_code, subject_name, location_id, city from honours_subject natural join locations;

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 - Which of the following query will result in an error?

A - select dept_id, avg(salary) from employees group by dept_id;

B - select avg(salary) from employees group by dept_id;

C - select dept_id, job_id, avg(salary) from employees group by dept_id, job_id;

D - select dept_id, count(name) from employees;

Q 6 - In which of the following cases a DML statement is executed?

A - When new rows are added to a table.

B - When a table is created.

C - When a transaction is committed.

D - None of the above.

Q 7 - A transaction starts when

A - A COMMIT statement is issued

B - A ROLLBACK statement is issued

C - A CREATE statement is used

D - All of the above

Q 8 - Which of the following is not true about a FOREIGN KEY constraint?

A - It is a referential integrity constraint.

B - It establishes a relationship between a primary key or a unique key in the same table or a different table.

C - A foreign key value cannot be null.

D - A foreign key value must match an existing value in the parent table.

Q 9 - Which of the following minimal code would create a sequence named loc_seq as a primary key of the LOCATIONS table?

A - create sequence loc_seq;

B - create sequence loc_seq on locations;

C - create loc_seq;

D - None of the above.

Q 10 - Which of the following is not true about database synonyms?

A - Synonyms are used for shortening lengthy object names.

B - A synonym is just an alternative name.

C - Synonyms can be created for tables, views, sequences, procedures and other database objects.

D - None of the above.