Differences between ER model and Reational model
Let’s see the difference between ER model and relational model:
ER model | Relational model |
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Developed by Peter Chen in 1976. | Developed by E.F. Codd in 1970. |
ER model is the high level or conceptual model. | It is the representational or implementation model. |
It is used by people who don’t know how database is implemented. | It is used by programmers. |
It represents collection of entities and describes relationship between them. | It represent data in the form of tables and describes relationship between them. |
It consists of components like Entity, Entity Type, Entity Set. | It consists of components like domain, attributes, tuples. |
It is easy to understand the relationship between entities. | It is less easy to derive the relationship between different tables. |
It describes cardinality. | It does not describe cardinality. |
E-R model does not define data dependencies. | Relational model defines dependencies in tables. |
E-R model represents relationships as associations. | Relational model represents relationships as join tables. |
E-R model is more granular in terms of data representation. | Relational model is less granular. |
E-R model is more flexible than the relational model. | Relational model is less flexible than E-R model. |
E-R model does not involve normalization. | Relational model involves normalization. |
E-R model use case is useful for initial planning and design. | Relational model use case is useful for implementation and maintenance |
Some of the popular Language and Notations used-
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Some of the popular Language and Notations used-
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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: