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 names of all the students whose email ids are not provided?

A - select first_name, last name from students where email = 0;

B - select first_name, last name from students where email = ‘ ‘;

C - select first_name, last name from students where email is null;

D - select first_name, last name from students where email = ‘null’;

Q 2 - What is returned by SUBSTR(‘TUTORIALS POINT’, 1, 9)?

A - TUTORIAL

B - POINT

C - TUTORIALS

D - UTORIALS

Q 3 - Which of the following is true about SQL joins?

A - The join condition is not separated from other search conditions in a query.

B - The ON clause makes code difficult to understand.

C - The join condition for natural join is basically an equijoin of all columns with same name.

D - None of the above.

Q 4 - 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 a full outer join

A - select h.subject_name, l.department_name, h.department_head, l.city from honours_subject h full outer join location l on(h.subject_code = l.subject_code);

B - select h.subject_name, l.department_name, h.department_head, l.city from honours_subject h full outer join location l on(subject_code);

C - select h.subject_name, l.department_name, h.department_head, l.city from honours_subject h full outer join location l where (h.subject_code = l.subject_code);

D - None of the above.

Q 5 - Which of the following is true about subqueries?

A - Subqueries could be used for Top-N analysis.

B - Subqueries can be of two types – single-row subquery and multiple-row subquery.

C - The outer and inner queries can get data from different tables.

D - All of the above.

Q 6 - Which of the following is true about inserting news rows to a table?

A - You must list values in the default order of the columns in the table.

B - You can also list the columns in the INSERT clause.

C - You can use the INSERT statement to add rows from one table to another.

D - All of the above.

Q 7 - Which of the following is true about the CREATE TABLE statement?

A - This is a DML statement.

B - This statement also record information in the data dictionary.

C - You don’t need any privilege to use this statement.

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 code will create an index named stu_marks_ind on the columns student_code and percentage_of_marks of the STUDENTS table?

A - It’s not possible to create an index on two columns.

B - create index stu_marks_ind from students(student_code, percentage_of_marks);

C - create index stu_marks_ind on students(student_code, percentage_of_marks);

D - create index stu_marks_ind (student_code, percentage_of_marks) on students;

Q 10 - A database administrator can

A - Create users.

B - Create privileges.

C - Grant privileges.

D - All of the above.