Normalisation

1. Normalisation

2. Un-normalised We know what data we want to store in our database Organise it into a table

3. Un-normalised

4. Un-normalised Problem: We can’t store more than one piece of data in one field

5. First Normal Form Rule: Remove all repeating groups

6. First Normal Form

7. First Normal Form Problems: We have empty fields? What happens if a student studies four courses? It’s really complicated to read

8. First Normal Form

9. First Normal Form Problem: We have redundant information

10. Second Normal Form Rule: All non-key attributes are dependant on the whole primary key This means: Make sure all data refers only to the primary key and only the primary key

11. Second Normal Form Student Courses

12. Second Normal Form To make them talk to each other: Enrolment

13. Second Normal Form Problem: What happens if a tutor teaches more than one course? We get more repeating and redundancy

14. Third Normal Form Rule: No attributes are dependant on other non-key attributes This means: Make sure no data refers anything other than the primary key

15. Third Normal Form Student Course

16. Third Normal Form Tutor Enrolment