Lecture 2 and ERD

The learning objectives for todays lecture was having a clear understanding of:

• the four principles of data modelling
• the difference in modelling techniques
• terminology and notation
• the 6 steps and objectives for ERD models.

4 principles of ER modelling are:

1. Identification of entities, relationship and structure
2. gives a process independant model
3. should result in a minimal data model
4. gives a logical model

6 steps of creating a good ERD:

1. identify entities
2. identfy each entities' attribute
3. put the data in logical groups
4. identify the primary keys
5. remove redundant data
6. identify and add relationships

:) Sam (: