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E-R Data Modeling Technique

Now we know various data models available. To understand the process of data modeling we'll study Entity Relationship model. Peter P. Chen originally proposed the Entity- Relationship (ER) model in 1976. The ER model is a conceptual data model that views the real world as a construct of entities and associations or relationships between entities.

A basic component of the model is the Entity-Relationship diagram, which is used to visually represent data objects. The ER modeling technique is frequently used for the conceptual design of database applications and many database design tools employ its concepts.

ER model is easy to understand. Moreover it maps easily to relational model. The constructs used in ER model can easily be transformed into relational tables. We will look into relational model in the next chapter, where other data models are discussed. In the following section, we'll look at E-R model concepts.

We can compare ER diagram with a flowchart for programs. Flow chart is a tool for designing a program; similarly ERD is a tool for designing databases. Also an ER diagram shows the kind and organization of the data that will be stored in the database in the same way a flowchart chose the way a program will run.

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