Data Models and ER Diagram Examples

This entity-relationship diagram example shows the data model of a lecture registration system.

An example entity-relationship diagram for a university information system.

An entity-relationship diagram for a database management system (DBMS).

An entity-relationship diagram that depicts the entities of the food ordering system.

Doctor and patient relationship depicted on an entity-relation diagram by Chen notation.

An entity-relationship diagram (Chen notation) for admin and user. It depicts the entities and their attributes.

An entity-relationship diagram for a voting system. It manages multiple votings and voter groups. Multiple voting options are supported for each voting.

An entity-relationship diagram for an event management system. The system allows its users to organize events, invite guests, and post information about the events.

An ER diagram for a multiplex cinema booking system. The data model allows a customer to reserve a seat for a scheduled movie.

An ERD example for an employee management system. The diagram may be used as an extensible template or base for your employee management system designs.

These ERD examples show a data model of a real estate portal. It depicts an entity for property offers and related entities. The database model also includes the customer part - a customer can create property wishlists and notifications for desired properties.

This ERD example shows model of an invoicing module. Each invoice has an issuer, a buyer and a list of product items.

This ER diagram example shows the data model of dynamic forms. If a form format is not strictly defined we need a dynamic structure that allows us to store various forms with a variable number of grouped fields. The fields may be of different types.

Model of user module including rights, roles and user access logging.

Example of entity-relationship diagram for a hotel room booking system.