Database normalization is the process of organizing data to minimize redundancy. It involves analyzing relations and dependencies between attributes and primary keys. There are several normal forms like 1NF, 2NF, 3NF that tables can be normalized to by removing anomalies and inconsistencies. An example database for an exam management system is presented showing how it can be normalized into multiple tables in 3NF to remove transitive dependencies between attributes. Contact details are provided at the end for more information on database design and normalization courses.

2. Anu. S
anusdhar4@gmail.com
www.facebook.com/AnuSasidharan
twitter.com/username
in.linkedin.com/in/profilename
DATABASE NORMALIZATION

3. Disclaimer: This presentation is prepared by trainees of
baabtra as a part of mentoring program. This is not official
document of baabtra –Mentoring Partner
Baabtra-Mentoring Partner is the mentoring division of baabte System Technologies Pvt . Ltd

4. DATABASE NORMALIZATION
LEVELS OF NORMALIZATION
SOLVED EXAMPLE

5. DATABASE NORMALIZATION
What is normalization????
Why normalize the database???
Strength and drawback of normalization..!!!

6. What is actually normalization???
The process of analyzing a given relational schema
based on their functional dependencies and
primary keys.

7. Why normalize database????
Minimizing redundancy
Accuracy
Performance

8. Strength And Drawback of Databases...!!!!
Strength:
Reduces Redundancy
Reduces errors
Drawback:
No of tables increases
Complexity increases

9. LEVELS OF NORMALIZATION
1NF
2NF
3NF
BCNF
4NF
5NF
DKNF
Redundancy
NumberofTables
Complexity

10. FIRST NORMAL FORM-1NF
A table is considered to be in 1NF if all the fields contain
only scalar values
Example (Not 1NF)
Pk_Int_Book_id Vchr_bookname Vchr_author
111 Basic Electrical and
Electronics
Engineering
Storey,Huggies,Tomasi
121 EVS Venugopal,Vinod

11. After performing 1NF
Pk_int_book_id Vchr_Bookname Vchr_author
111 Basic Electrical and
Electronics Engineering
Storey
111 Basic Electrical and
Electronics Engineering
Huggies
111 Basic Electrical and
Electronics Engineering
Thomasi
121 EVS Vinod
121 EVS Venugopal

12. Second Normal Form
For a table to be in 2NF, there are two requirements:
 The database is in first normal form
 All non_key attributes in the table must be functionally
dependent on the entire primary key

13. Second Normal Form- Example
Database not in 2NF:
Pk_Vchr_Emp_name Pk_Vchr_emp_desig Int_Emp_Sal Vchr_emp_address
Paul Manager 60000 121,PK
street,Mumbai
Ram Clerk 5000 111/114, Arumugam
street, Chennai
Primary key : {vchr_emp_name,vchr_emp_desig}
Here the employee salary is dependant on both primary keys employee address is
not dependant on employee designation. Hence it is not in 2NF

14. Second Normal Form- Example
Database after performing 2NF:
Pk_Vchr_Emp_n
ame
Pk_Vchr_emp_d
esig
Int_Emp_Sal
Paul Manager 60000
Ram Clerk 5000
Pk_Vchr_Emp_name Vchr_Emp_address
Paul 121,PK street,Mumbai
Ram 111/114, Arumugam street,
Chennai

15. THIRD NORMAL FORM
For a table to be in 3NF, there are two requirements:
 The table should be second normal form
 No attribute is transitively dependent on the primary key
All non key attributes of a table must be functionally dependent on
a candidate key.
There must be no interdependencies among non-key attributes

16. Third Normal Form- Example
Database not in 3NF:
Pk_int_stud_id Vchr_stud_name Int_class_id Vchr_class_name
3457 Ashish 101 CS5
4332 Abhay 121 EC6
Primary key : {pk_vchr_emp_name}
Here Student name , and class_id depends on primary key pk_int_stud_id.
The class name is but more dependant on the class_id (non-key) than stud_id.
So there is a transitive dependency. Hence not in 3NF.

17. Third Normal Form- Example
Database after performing 3NF:
Pk_int_stud_id Vchr_stud_name Int_class_id
3457 Ashish 101
4332 Abhay 121
Pk_Int_class_id Vchr_class_name
101 CS5
121 EC6

18. AN EXAMPLE TO SOLVE
Exam Management System
-----------------------------------
Users:
Admin
Student
Admin
---------
Login
View Profile
Edit Profile
Facility to manage student
Facility to manage exam
Student
----------
Attend exams
View mark

19. Let us first list the required tables:
Login_table
User_table
Exam_table
Exam_qstn_table
Qstn_option_table
Stud_answer_table
SOLVING THE PROBLEM

20. Pk_int_login_id Vchr_username Vchr_password
1 Administrator Admin
2 Ashish Ashish123
3 Abhay abhay123
Login_table
User_table
Pk_int_
user_id
Vchr_
Fname
Vchr_
Lname
Dat_dob Vchr_
place
Bln_status Vchr_user_
type
1 Pratap Nair 1867-05-01 Calicut 1 Admin
2 Ashish Prakash 1993-02-01 Banglore 1 Student
3 Abhay Anandh 1992-03-11 Chennai 1 Student

21. Pk_int_exam_id Vchr_exam_name int_exam_duration
(in hrs)
101 Basic C
programming Test
1
102 Cpp Evaluation test 1
Exam_table
Exam_qstn_table
Pk_int_qstn_id Fk_int_exam_id Vchr_question Vchr_answer Int_marks
1111 101 Code1 21 5
1112 101 Code2 11122133 10
1113 102 Code3 131 5
1114 102 Code4 3333 10

22. Question_option_table
Pk_int_option_id Fk_int_qstn_id Vchr_option
1 1111 21
2 1111 22
3 1111 25
4 1112 11122133
5 1112 0
6 1112 11100000
7 1113 131
8 1113 100
9 1113 1
10 1114 3333
11 1114 0
12 1114 2222

23. Student_answer_table
Pk_int_
answer_id
Fk_int_qstn_id fk_int_user_id Vchr_stud_
answer
Int_mark_
scored
116 1111 2 22 0
117 1112 2 11122133 10
118 1113 2 131 5
119 1114 2 3333 10
120 1111 3 21 5
121 1112 3 11122133 10
122 1113 3 131 5
123 1114 3 0 0

24. THANK YOU...

25. Want to learn more about programming or Looking to become a good programmer?
Are you wasting time on searching so many contents online?
Do you want to learn things quickly?
Tired of spending huge amount of money to become a Software professional?
Do an online course
@ baabtra.com
We put industry standards to practice. Our structured, activity based courses are so designed
to make a quick, good software professional out of anybody who holds a passion for coding.

26. Follow us @ twitter.com/baabtra
Like us @ facebook.com/baabtra
Subscribe to us @ youtube.com/baabtra
Become a follower @ slideshare.net/BaabtraMentoringPartner
Connect to us @ in.linkedin.com/in/baabtra
Thanks in advance.
www.baabtra.com | www.massbaab.com |www.baabte.com

27. Contact Us
Emarald Mall (Big Bazar Building)
Mavoor Road, Kozhikode,
Kerala, India.
Ph: + 91 – 495 40 25 550
NC Complex, Near Bus Stand
Mukkam, Kozhikode,
Kerala, India.
Ph: + 91 – 495 40 25 550
Cafit Square,
Hilite Business Park,
Near Pantheerankavu,
Kozhikode
Start up Village
Eranakulam,
Kerala, India.
Email: info@baabtra.com