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 where the second letter in the first name is ‘i’?

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

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

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

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

Q 2 - Which of the following is not true about single row functions?

A - They operate on single rows only and return one result per row.

B - They accept arguments that could be a column or any expression.

C - They cannot be nested.

D - They may modify the data type.

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 true about a group function?

A - Group functions operate on sets of rows to produce multiple results per group.

B - DISTINCT keyword makes a group function consider duplicate values.

C - Group functions ignore null values.

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 not true about inserting news rows to a table?

A - The INSERT INTO statement is used for inserting new rows to a table

B - You cannot insert rows with NULL values to a table.

C - You may insert a new row containing values for each column.

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 is not true about simple views?

A - They derive data from one table.

B - They contain no functions or grouping.

C - You cannot perform DML operations through a simple view.

D - All of the above are true.

Q 9 - Which of the following is not true about a sequence?

A - They are used for generating sequential numbers.

B - Sequences are created by the CREATE SEQUENCE statement.

C - You cannot modify a sequence.

D - None of the above.

Q 10 - Which of the following code would allocate the privileges of creating tables and view to the role named student_admin?

A - grant create table, create view to student_admin;

B - grant to student_admin create table, create view;

C - grant role student_admin create table, create view;

D - None of the above.