Entity-Relationship Model, Relational Model

Entity-Relationship Model:-

ER Model is the conceptual design of a database. In Entity-Relationship (ER) Model we can represent real-world entities with attributes and relationships among them. ER Model is used to create entity set, relationship set and constraints.

ER Model has two major concepts −

1. Entities and their attributes.

2. Relationships among entities.

In ER model, to represent entity or entity set, relationship or relationship set, attributes, aggregation, specialization, generalization etc. Following signs or symbols are used.

KEY BENEFITS OF USING ENTITY RELATIONSHIP DIAGRAMS:-

Visual Representation

Effective communication

Easy To Understand

High flexibility

Relational Model:-

The most popular data model in DBMS is the Relational Model. In Relational Model, Data is stored in tables called relations. Each row in a relation is called tuple and contains a unique value. 

Each column of relation shows contains values from a same domain.