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What is an Entity Relationship Diagram (ERD)?

Relationships between entity sets stored in a database are illustrated in an entity relationship diagram (ERD).In this context, an entity is an object, a component of data. An entity set is an aggregate of entities with similar properties.Each entity may have attributes that define its properties.

ERD diagrams illustrate the logical structure of databases by defining the entities, attributes, and relationships between them.

ER diagrams illustrate how a database is designed.


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Documenting an Existing Database Using Data

It is important to create a database diagram for two reasons.It might be that you are creating a new schema, or you are documenting your existing one.

Using data directly from your database, create a database diagram to document your existing database.If your database structure is a CSV file (some scripts will help you do this here), then you can have a program generate an ERD automatically.

This will represent your database in the most accurate way and will require no drawing on your part.

Following is an example of a very basic database structure generated from data.

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Creating a new plan is also as easy as editing the generated diagram and collaborating with your team.

Get to know curiouslyravenous.com's ERD extension for generating ER diagrams from data automatically.

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The History of Entity Relationship Diagrams

He developed the first ERDs in 1976.Charles Bachman and James Martin have made a few minor amendments since then to the basic ERD principles.

Common Entity Relationship Diagram Symbols

The ER diagram illustrates how information is related within a system.The five main components are:

Incorporations
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Implementation
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Aspects
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The connecting linesIndications of coordination
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This is the information engineering style
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A. Yang's Style
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Style: Bach
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Mr. Styles
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ERD Explained

Here's a short video showing how ERD diagrams work and the components.


ER Diagram Uses

By documenting a system or process in multiple ways, we increase our understanding of it.ERD diagrams are typically used in conjunction with data flow diagrams to show the contents of a data store.Visualizing how data is connected is particularly useful when building a relational database.

Entity Relationship Diagram Tutorial

To create an ERD, follow these best practices:

You will need to identify the entities.
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Relationships must be identified.Explain the relationship.Affix attributes.Fill out the diagram.

Tips for Effective ER Diagrams

Entity Relationship Diagram Examples