ER MODEL

ER MODEL:

• Entity Relationship Model
• The entity-relationship model (or ER model) is a way of graphically representing the logical relationships of entities (or objects) in order to create a database.
• The ER model was first proposed by Peter Pin-Shan Chen of Massachusetts Institute of Technology (MIT) in the 1970s.

Basic elements of ER Models are:

• Entity
• Entity Sets
• Attributes
• Relationships

1.  Entity:


       Entity is an Object whose data is to be stores in the Database.

       
























2. Entity Sets


     Collection of entities that share common properties is called Entity Sets.
     It is represented by

3. Attributes


     Entity properties are called Attributes. They are also called as "Fields".






4. Relationships