Dbs101_flippedclass_2
Topic: Exploring ER model Representation.
For me, Entity Relational(ER) models are for identifying entities to be represented in a database and see how these entities are related to each other. It also shows the schema(design) of a specific databse and overall logic of database graphically which makes it easier for the developers to know the data more clearly.
Advantages of ER Model
ER models require no technical knowledge to understand them and no hardware to suppoert them.
These model are easy to understand and easy to create for naive users.
It is easy to visualize the data and have a standard solution of the data logic.
### Entity Entities are the main points in an ER model example, like a stem of a plant. They are represented by the means rectangle and the rectangle are named with the set they represent.
### Attributes They are the sub point of a entity example, the branches of a plant. they are represented by by the means of ellipse and every ellipes represents each attribute which are directly connected to the entity.
If the attributes are complex and composite they are further divided into ellipes that connected to the main eliipse and to the entity.
Multivalue attributes: thses are attrbutes that can contain more than one value and are represented by double oval.
Derived Attributes: are those attributes that can be derived from other attributes.
