Difference between E-R Model and Relational Model in DBMS

In database management systems (DBMS), two key methods are the Relational model and the Entity-Relationship (E-R) model. Each has a specific function in the development and operation of databases. While the Relational model provides the practical structure for organizing and managing data in relational databases, the E-R model concentrates on offering a conceptual framework for comprehending the relationships between entities.

The E-R model and the Relational model are two types of data models present in DBMS. Let's have a brief look at them: 

What is the E-R Model?

The E-R model stands for the Entity-Relationship model. ER Model is used to model the logical view of the system from a data perspective which consists of these components: Entity, Entity Type, Entity Set. An Entity may be an object with a physical existence – a particular person, car, house, or employee – or it may be an object with a conceptual existence – a company, a job, or a university course. An Entity is an object of Entity Type and a set of all entities is called an entity set. e.g.; E1 is an entity having Entity Type Student and a set of all students is called Entity Set. An Entity Type defines a collection of similar entities and a set of all entities is called an entity set. 

What is the Relational Model?

The Relational Model was proposed by E.F. Codd to model data in the form of relations or tables. After designing the conceptual model of the Database using an ER diagram, we need to convert the conceptual model into a relational model that can be implemented using any RDBMS language like Oracle SQL, MySQL, etc. Consider a relation STUDENT with attributes ROLL_NO, NAME, ADDRESS, PHONE, and AGE shown in Table 1.

STUDENT

Differences Between ER Model and Relational Model

Let’s see the difference between ER model and relational model:

Conclusion

The Relational model is a practical implementation that uses tables for data storage, whereas the E-R model is a high-level conceptual tool for visualizing entities and relationships. Relational offers the framework for database systems, combining conceptual clarity with effective implementation, whereas E-R helps with design.