Normalisation

Normalisation is to find out the entities and attributes within given data.

5 steps of Normalisation

1. Write down the unnormalised data
2. choose key for main group
3. extract repeating groups into separate entities and choose key
4. identify and extract partial key dependencies
5. identify and extract non key dependencies

0NF - write down all of the unnormalised data. once used data first then data that is used more than once appears second

1NF - choose keys for the data in the list (what is needed for the data to connect)

2NF - extract partial key dependencies (what remaining from the seperate entities do not depend on the key it is under)

3NF - extract non key dependencies (what is remaining from the seperate entities that could be used as a seperate entity on their own)