Boyce-Codd Normal Form (3.5 NF).
A database is in BCNF if following conditions met;
- It is in 3NF(1NF: no repeating groups, 2NF: Full functional dependency must exist and avoid partial dependency, 3NF: Avoid Transitive Dependency).
- For every functional dependency X->Y, X should be the super key of the table (Non-prime attribute never determines prime attribute).
Example
For example, we have a table, with some data. The given table is not in BCNF.
| Author | Nationality | Book title | Category | Number of pages |
| Author_A | Pakistani | Data Mining Concepts by T4Tutorials | Comedy | 700 |
| Author_B | Indian | Database Systems by T4Tutorials | Textbook | 350 |
| Author_C | American | Software Engineering Concepts by T4Tutorials | Textbook | 300 |
| Author_D | American | Software Engineering Concepts by T4Tutorials | Textbook | 300 |
| Author | Nationality |
| Author_A | Pakistani |
| Author_B | Indian |
| Author_C | American |
| Author_D | American |
| Book title | Category | Number of pages |
| Data Mining Concepts by T4Tutorials | Comedy | 700 |
| Database Systems by T4Tutorials | Textbook | 350 |
| Software Engineering Concepts by T4Tutorials | Textbook | 300 |
| Author | Book title |
| Author_A | Data Mining Concepts by T4Tutorials |
| Author_B | Database Systems by T4Tutorials |
| Author_C | Software Engineering Concepts by T4Tutorials |
| Author_D | Software Engineering Concepts by T4Tutorials |
Video Lecture
Excercise 1NF to 5NF
CEO @ T4Tutorials.com
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I welcome to all of you if you want to discuss about any topic. Researchers, teachers and students are allowed to use the content for non commercial offline purpose. Further, You must use the reference of the website, if you want to use the partial content for research purpose.
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