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.
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 |
Exercise 1NF to 5NF
Read Tutorials about Normalization in DBMS
- First Normal form in DBMS
- Second normal form Examples in DBMS
- Third normal form
- Boyce-Codd Normal Form (3.5 NF)
- Fourth Normal Form
- Fifth Normal Form (5NF)
