Database Management System

Topics in this chapter

• DBMS Fundamentals and Architecture
• Database Models and Schema
• Entity Relationship Modeling
• Relational Tables and Keys
• SQL Queries and Commands
• Normalization and Data Integrity
• Database Security and Transactions

Cheat sheet

Practice questions

1. Question 1Q-61d54a

   Whatever whatever we do do do ???

   1. A.we do ?
   2. B.They do ?
   3. C.really ?
   4. D.not really ?
   See the answer and solution
2. Question 2Q-D1D6CE

   Test

   See the answer and solution
3. Question 3Q-9A4967

   A relation named STUDENT has attributes RollNo, Name, Class and Email. RollNo is unique and never contains a NULL value, while the other attributes may contain duplicate values. Which attribute is most suitable as the primary key?

   1. A.Name
   2. B.Class
   3. C.RollNo
   4. D.Email
   See the answer and solution
4. Question 4Q-BE5DF8

   A relation named Employee has the attributes EmpID, EmpName, Department and Salary. Which SQL query displays the names of employees who belong to the IT department, earn more than 50000, and whose names are arranged in ascending alphabetical order?

   1. A.SELECT EmpName FROM Employee WHERE Department = 'IT' AND Salary > 50000 ORDER BY EmpName ASC;
   2. B.SELECT EmpName FROM Employee WHERE Department = 'IT' OR Salary > 50000 ORDER BY EmpName ASC;
   3. C.SELECT EmpName FROM Employee WHERE Department = 'IT' AND Salary < 50000 ORDER BY EmpName DESC;
   4. D.SELECT EmpName FROM Employee ORDER BY Department = 'IT' AND Salary > 50000;
   See the answer and solution
5. Question 5Q-B67FC5

   Explain why storing several phone numbers as a single comma-separated value in one attribute violates First Normal Form (1NF). Suggest a suitable relational design to store multiple phone numbers for each customer.

   See the answer and solution