Table of Contents
1. Introduction to Normalization
2. Steps to Convert Database Table into First, Second and Third Normal Forms
3. Illustration – Reason to Convert Database Table into First, Second and Third Forms
4. Explain Situations when De-Normalization is Acceptable with an Illustration
5. Impact of Business Rules on Database Normalization and Decision to De- normalize it
The process to organize a data in a database efficiently is termed as Normalization. With an aim to eliminate redundant data and ensuring the logic of data dependency, normalization is a process used by various businesses and colleges for efficient data ...view middle of the document...
2.3 Conversion to Third Normal Form
To convert database to 3NF, following guidelines need to be followed –
* You need to satisfy the requirements of 2NF
* Eliminate those columns that are not reliant on the primary key
3. Illustration – Reasons for Conversion of Database to 1NF, 2NF and 3NF.
Let’s illustrate an example that shows the reason to convert the database table to 1NF, 2 NF and 3NF.
Student details | Course details | Result details |
| | |
1001 Joseph 11/09/1986 | M4 basic maths 7 | 11/11/2004 89 A |
1002 Michelle 12/08/1987 | M4 basic maths 7 | 11/11/2004 78 B |
1001 Joseph 23/06/1987 | H6 4 | 11/11/2004 87 A |
1003 Amanda 16/07/1985 | C3 basic chemistry 11 | 11/11/2004 90 A |
1004 Christina 24/09/1988 | B3 8 | 11/11/2004 78 B |
1002 Michelle 23/06/1988 | P3 basic physics 13 | 11/11/2004 67 C |
1005 Joe 14/09/1987 | P3 basic physics 13 | 11/11/2004 78 B |
1003 Amanda 23/10/1987 | B4 5 | 11/11/2004 67 C |
1005 Joe 13/03/1990 | H6 4 | 11/11/2004 56 D |
1004 Christina 21/08/1987 | M4 basic maths 7 | 11/11/2004 78 B |
Though this table seems to be very well organized but looking at it carefully, you will come across various anomalies. Let now look at how converting it to 1NF, 2NF and 3NF will make it more efficiently organized.
Converting it to the first normal form, we will remove any duplicate content found in the original table and form separate column for each group like – Student’s details, Course details and Result details. Once we do this we convert it to second form for more organization.
Second normal form exists when the table is in first form and no dependency exists between key and non-key attributes. We organize the second form by creating separate groups – Student table will have three columns stating the roll number of student, their names and their date of birth. Similarly the...