Data Modelling

The four principles of entity relationshops are:
1) Identification of entities
2) Construction of a process independant of the stored data requirements.
3)Construction of a rebust data model.
4) The construction of a logical model of the data.

The six steps in creating a good entity relationship diagram:

1) Identify data object (entities).
2) List the attributes.
3) Data in logical groups.
4) Identify Primary Keys.
5) Eliminate redundancy
6) Investigate and record relationships.