Author
Home > Technology > What is the Difference Between ER and EER Diagram?

Guilherme Mazui

•4 minutes to read

What is the Difference Between ER and EER Diagram?

🆚 Go to Comparative Table 🆚

The main difference between Entity-Relationship (ER) and Enhanced Entity-Relationship (EER) diagrams lies in the level of detail and the additional features provided by EER diagrams. Here are the key differences:

  1. Level of Detail: ER diagrams provide a visual representation of the relationships and attributes of entities in a database, offering a basic outline of the system. EER diagrams, on the other hand, go into greater detail by including elements that allow for aggregation, generalization, and specialization.
  2. Inheritance Support: EER diagrams support the concepts of inheritance (generalization and specialization), which are not present in ER diagrams. Generalization combines lower-level entities into a higher-level entity, while specialization divides high-level entities into lower levels.
  3. Aggregation: EER diagrams include aggregation, which allows two entities to be treated as a single one for more efficient data organization and placement. ER diagrams do not support this feature.
  4. Application: ER diagrams are generally used for designing databases with simpler structures, while EER diagrams are better suited for databases with a larger amount of data and more complex relationships.

When deciding which diagram is best for your project, consider the level of detail, the complexity of the data, and the specific features you need for your database design. If your database contains a larger amount of data and more complex relationships, an EER diagram may be more appropriate. However, if you are working with a simpler system, an ER diagram might be sufficient.

On this page
  • What is the Difference Between ER and EER Diagram?
  • Comparative Table: ER vs EER Diagram

    • Comparative Table: ER vs EER Diagram

    The main difference between Entity-Relationship (ER) and Enhanced Entity-Relationship (EER) diagrams lies in the level of detail and the additional features provided by EER diagrams. Here is a comparison table showing the differences between the two types of diagrams:

    Feature ER Diagram EER Diagram
    Purpose Visual representation of data based on ER model, focusing on relationships between entities in a database. More comprehensive representation of data based on EER model, an extension of the original ER model, incorporating additional features such as subclasses, superclasses, specialization, generalization, and relationship inheritance.
    Relationships Depicts one-to-one, one-to-many, and many-to-many relationships between entities. Builds upon ER relationships, includes additional elements for aggregation, generalization, and specialization.
    Entities Represents entities as tables and attributes of the entities. Connects entities using a system of notation called crow's foot notation. Expands upon ER entities by incorporating attributes, relationships inheritances, and the ability to sort and group relationships for efficient placement.
    Applications Ideal for small to medium-sized databases with straightforward relationships. Useful for larger databases with more complex relationships and properties.

    In summary, while both ER and EER diagrams are used to design and represent the structure of a database, EER diagrams offer a more detailed and comprehensive representation by incorporating additional features such as entities, relationships, generalization, specialization, and aggregation.

    Read more:

    Guilherme Mazui

    Guilherme Mazui is graduated in journalism from the Federal University of Minas Gerais (UFMG) and a master's degree in Communication from the University of São Paulo (USP). In addition, he has experience in advertising writing and has worked as a content editor in several companies.