DBMS Lab quizII

.  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’?

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

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

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

• select first_name from students where first_name like ‘A’; 

You have a relation called "Employees" that contains information about employees, including their salaries. You want to find the average salary of all employees. Which relational algebra operation would you use?

• SELECT

• PROJECT

• AGGREGATE

• JOIN

With SQL, how can you return the number of not null records in the “Persons” table?

• SELECT COUNT() FROM Persons

• SELECT COLUMNS() FROM Persons

• SELECT COLUMNS(*) FROM Persons

• SELECT COUNT(*) FROM Persons

You have a "Products" relation that contains information about products, including their prices. You want to find the products with a price greater than $100. What relational algebra operation would you use?

• SELECT

• PROJECT

• JOIN

• DIFFERENCE

SQL query to find the temperature in increasing order of all cities.

• SELECT city FROM weather ORDER BY temperature

• SELECT city, temperature FROM weather

• SELECT city, temperature FROM weather ORDER BY temperature

• SELECT city, temperature FROM weather ORDER BY city

In a database, you have a "Sales" relation that contains information about sales transactions, including the salesperson's name. You want to find the distinct names of salespeople who made sales. What relational algebra operation would you use?

• SELECT

• PROJECT

•  UNION

• DISTINCT

SQL query to find all the cities whose humidity is 95.

• SELECT city WHERE humidity = 95

• SELECT city FROM weather WHERE humidity = 95

• SELECT humidity = 89 FROM weather

• SELECT city FROM weather

       A database contains a table named employees with columns employee_id, employee_name, and salary. A user initiates a transaction to increase the salary of all employees by 10%. Which SQL statement should be used to update the salary within the transaction?

• UPDATE employees SET salary = salary * 1.10;

• MODIFY employees SET salary = salary * 1.10;

• ALTER employees SET salary = salary * 1.10;

• CHANGE employees SET salary = salary * 1.10;

      Find all the cities with temperature, condition and humidity whose humidity is in the range of 63 to 79.

• SELECT * FROM weather WHERE humidity IN (63 to 79)

• SELECT * FROM weather WHERE humidity NOT IN (63 AND 79)

• SELECT * FROM weather WHERE humidity BETWEEN 63 AND 79

• SELECT * FROM weather WHERE humidity NOT BETWEEN 63 AND 79

A database contains a table named orders with columns order_id, customer_id, and total_amount. A user initiates a transaction to delete all orders with a total amount less than $50. Which SQL statement should be used to delete these records within the transaction?

• REMOVE FROM orders WHERE total_amount < 50;

• DELETE * FROM orders WHERE total_amount < 50;

• DELETE FROM orders WHERE total_amount < 50;

• DROP FROM orders WHERE total_amount < 50;