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There are three basic elements in an ER Diagram: entity, attribute, relationship. There are more elements which are based on the main elements. They are weak entity, multi valued attribute, derived attribute, weak relationship, and recursive relationship.

The components include: Entities, which are objects or concepts that can have data stored about them.Attributes, which are properties or characteristics of entities.The relationships between and among those entities. Actions, which describe how entities share information in the database. Connecting lines.

Enhanced entity-relationship diagrams are advanced database diagrams very similar to regular ER diagrams which represent requirements and complexities of complex databases. It is a diagrammatic technique for displaying the Sub Class and Super Class; Specialization and Generalization; Union or Category; Aggregation etc.

There are two kinds of ER diagrams: conceptual and physical. Conceptual diagram models can provide the foundation for logical data models or show commonality relationships between ER models as a basis for data-model integration.

An entity relationship diagram (ERD), also known as an entity relationship model, is a graphical representation that depicts relationships among people, objects, places, concepts or events within an information technology (IT) system.

A mandatory relationship indicates that for every occurrence of entity A there must exist an entity B, and vice versa. When specifying a relationship as being mandatory one-to-one, you are imposing requirements known as integrity constraints.

Entity Relationship Diagram (ERD) Symbols and Notations. There are three basic elements in an ER Diagram: entity, attribute, relationship. There are more elements which are based on the main elements. They are weak entity, multi valued attribute, derived attribute, weak relationship, and recursive relationship.

In the mandatory participation, for every instance of entity A, there must exist an instance of entity B and vice versa. An example of Mandatory participation would be relationship between mother and child.

What are the components of an entity-relationship diagram? ER diagrams or ERD's are composed of three main elements: entities, attributes, and relationships. Entities - typically displayed in a rectangle, entities can be represented by objects, persons, concepts, or events that contain data.

There are three types of relationships that can exist between two entities. One-to-One Relationship. One-to-Many or Many-to-One Relationship. Many-to-Many Relationship.