Design and implementation of a web portal on sustainable development in Cameroon

· Normalisation of associations

Associations should be materialise with verb in the infinitive form or eventually in the passive form.

5.3.6.1. First Normal Form (1NF)

A relation is in first normal form if:

- All attributes contain only one atomic value (not divisible).

- The attributes do not contain repetitive values.

5.3.6.2. Second Normal Form (2NF)

A relation is in second normal form if:

- She is in first normal form.

- If all the non-key attributes do not depend on a part of the primary key.

In other words, any property of the relationship must depend entirely of the key.

5.3.6.3. Third Normal Form (3NF)

A relation is in third normal form if:

- She is in second normal form.

- If all functional dependencies on the key are direct (if there is no transitive functional dependencies between non-key attributes).

In other words, all of the attributes do not belong to the key does not depend on a non-key attribute.