ENTITY RELATIONSHIP DIAGRAM

 ENTITY RELATIONSHIP DIAGRAM

An entity relationship diagram (ERD) is a sort of diagram that demonstrates the relationships between various entities (such as users, clients, or other objects) in an application or database. They are made when a new system is being designed so that the database's structure can be understood by the development team. They can also be built on an existing system to assist the team in figuring out how it operates and identifying and fixing any problems. (Database Star, 2019)

RELATIONSHIP

A relationship in an ERD defines how two entities are related to each other. They can be derived from verbs when speaking about a database or a set of entities.(Database Star, 2019)

ENTITY

An entity is an object about which data can be kept. It can be a real thing (like a car or a person), an idea (like an address), or an occasion (e.g. student enrolment in a course). They stand in for nouns.(Database Star, 2019)

ATTRIBUTE

An attribute is a property of an entity or something that can be used to describe an entity. They are often represented as ovals, or as entries inside an entity.(Database Star, 2019)

CARDINALITY

The term "cardinality" refers to how many instances of a given entity there are when there is a relationship between two entities. This is frequently written as a number, although depending on the type of diagram used, it could alternatively be a symbol. Zero, one, and many are typical values for cardinality.(Database Star, 2019)

Reference list

Database Star. (2019). A Guide to the Entity Relationship Diagram (ERD). [online] Available at: https://www.databasestar.com/entity-relationship-diagram.

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