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 whose first name starts with the character ‘A’?

A - select first_name from students where first_name like ‘A%’;

B - select first_name from students where first_name like ‘%A’;

C - select first_name from students where first_name like ‘%A%’;

D - select first_name from students where first_name like ‘A’;

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

A - 789.84

B - 789.83

C - 78

D - 789.00

Q 3 - You want to calculate the tax payable by the employees of an organization. If the employee gets a commission, then the tax would be calculated on commission plus salary, if the employee does not get any commission, then the tax would be calculated on salary only. Which function should you use for calculating tax?

A - NVL

B - NVL2

C - NULLIF

D - COALESCE

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 is not true about single-row subqueries?

A - Single row subqueries return one row from the inner SELECT statement.

B - Single row subqueries return one row from the outer SELECT statement.

C - Single row subqueries use single-row comparison operators.

D - All of the above.

Q 6 - Which of the following is true about removing rows from a table?

A - You remove existing rows from a table using the DELETE statement

B - No rows are deleted if you omit the WHERE clause.

C - You cannot delete rows based on values from another table.

D - All of the above.

Q 7 - Consider the following schema −

LOCATIONS(subject_code, department_name, location_id, city);

Which code snippet will alter the table LOCATIONS and delete the column named CITY?

A - MODIFY TABLE locations DROP (city varchar2(30));

B - ALTER TABLE locations DROP COLUMN city;

C - ALTER TABLE locations DROP (city);

D - None of the above.

Q 8 - Which of the following is not true about use of a database view?

A - It restricts data access.

B - It makes queries easy.

C - It provides data independence.

D - It prevents different views of same data.

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 code would grant the role student_admin to a user named william?

A - grant student_admin to william;

B - grant to william student_admin;

C - grant william student_admin;

D - None of the above.