What is ERD? (Definition, Components and Functions)


What is ERD? – Have you ever heard of ERD? Or is this term still foreign to your ears? Because ERD is a term that is included in the category of the IT world, it is only natural that some of you still don’t know it. Now to discuss further, let’s look at the information we share below.

In accordance with what was stated above, this time we will discuss several things related to ERD. That is, starting from understanding what ERD is, its types, models, and online tools that are usually used to create ER diagrams. Making this ER diagram is usually done by a data engineer and data analyst.

What is an ERD?

Entity Chart
Entity Chart

ERD or which has an abbreviation as Entity Relationship Diagram is a design or model in describing data that has a relationship and is compiled or poured in the form of a design. This ER diagram is usually used as a model or database design so that later the database system created can be arranged in a more structured and neat manner.

Types of ER Diagram Data Models

Why are we discussing the types of data models too?. This is of course because to compile a database system, we must determine the data model that will be used. The selection of this data model will later affect the software development or project being developed.

  1. Logical Data Types, to create a logical data model does not require a conceptual data model. The components in the login data model include entities, operations, transactions that have been defined.
  2. Physical Data Types, this data model is usually used to determine structural metadata in database management systems as data storage media that are interconnected or relational.

ERD Components

  1. An entity is a set of objects that can be uniquely identified.
  2. Attribute, this component is used to describe the characteristics of an entity. Types of attributes used in ERD:
    – Key attribute, is an attribute that is used to describe and determine unique data.- Simple attribute, is an attribute that has a single value and cannot be broken down again.- Multivalue attribute, is an attribute that has several values ​​in each entity.- Combined Attribute, is an attribute that is grouped into sub-attributes, each of which has a meaning. – Derivative Attributes, are attributes that do not have to be in the ERD.
  3. Relationship, is a relationship between one entity with another entity that comes from different entity groups.
  4. Line, serves as a liaison between attributes.

So much information that we can provide regarding ERD along with related explanations, hopefully the information we provide is useful, thank you.