N1 & C1 DBMS LAB QUIZ

As part of our ongoing efforts to improve our customer database, you've been tasked with adding a new column to the 'Customers' table to store email addresses. This will help us communicate with our customers more effectively. Which SQL statement should you use to accomplish this?

• A) ALTER TABLE Customers ADD Email VARCHAR(100);

• B) UPDATE Customers SET Email = '[e-mail]';

• C) CREATE COLUMN Email IN Customers;

• D) INSERT INTO Customers (Email) VALUES ('[e-mail]');

In your role as data analysts, you often work with a customer database that evolves over time to accommodate new information. Your manager has requested you to update the database by adding new attributes to an existing customer relation. Which of the following commands should you use to accomplish this task effectively?

• A. Alter

• B. Modify

• C. Tailor

• D. Eliminate

In the financial database you oversee, there's a need to periodically clear out all the transaction records from a particular table without generating extensive log entries for each deletion. This process ensures efficient data maintenance. Which SQL statement should you employ to achieve this specific task?

• DELETE

• DROP

• TRUNCATE

• REMOVE

In a given relationship R, if an attribute A uniquely defines all other attributes, then the attribute A is a key attribute which is also known as the _________ key.

• Candidate
  

• Join
  

• Functional
  

• None of the Mentioned

By normalizing relations or sets of relations, one minimizes ___.

• 1. Data

• 1. Fields

• 1. Redundancy

• 1. Database

As part of our annual salary adjustments, we need to update the 'Salary' column for all employees in the 'Employees' table who belong to the 'HR' department. This ensures that our HR team is fairly compensated. Which SQL statement should you use to accomplish this?

• A) UPDATE Employees SET Salary = 55000 WHERE Department = 'HR';

• B) INSERT INTO Employees (Salary) VALUES (55000) WHERE Department = 'HR';

• C) DELETE FROM Employees WHERE Department = 'HR';

• D) SELECT * FROM Employees WHERE Department = 'HR';

As part of your role as a database developer, you are responsible for ensuring the integrity of the data in our company's employee database. This involves using various SQL constraints to maintain data quality. However, not all options provided are actual SQL constraints. Can you identify which one is not a constraint?

• A. Not Null

• B. Check

• C. Union

• D. Primary Key

A common approach to normalization is to ___ the larger table into smaller tables and link them together by using relationships.

• 1. Add

• 1. Subtract

• 1. Multiply

• 1. Divide

You are designing a database for an online store. You want to ensure that product prices are always greater than or equal to $5. Which SQL constraint should you use to enforce this rule?

• A) PRIMARY KEY

• B) CHECK

• C) FOREIGN KEY

• D) UNIQUE

You are developing a database for a car rental company. You need to retrieve a list of available cars for rent on a specific date. Which SQL query should you use?

• A) SELECT * FROM Cars WHERE status = 'Available' AND rental_date = '2023-09-15';

• B) SELECT * FROM Cars WHERE status = 'Rented' AND rental_date <> '2023-09-15';

• C) SELECT * FROM Cars WHERE status = 'Available' AND rental_date IS NULL;

• D) SELECT * FROM Cars WHERE status = 'Available' AND 'rental_date' = '2023-09-15';