This site uses cookies. By continuing to browse the ConceptDraw site you are agreeing to our Use of Site Cookies.
"In software engineering, an entity–relationship model (ER model) is a data model for describing a database in an abstract way.Chen's notation for entity–relationship modeling uses rectangles to represent entity sets, and diamonds to represent relationships appropriate for first-class objects: they can have attributes and relationships of their own. If an entity set participates in a relationship set, they are connected with a line.
Attributes are drawn as ovals and are connected with a line to exactly one entity or relationship set." [Entity–relationship model. Wikipedia]
This sample Chen's ER-diagram illustrates the structure of a typical MMORP game.
"Massively multiplayer online role-playing game (MMORPG) mixes the genres of role-playing video games and Massively multiplayer online games, possibly in the form of web browser-based games, in which a very large number of players interact with one another within a virtual world.
As in all RPGs, players assume the role of a character (often in a fantasy world or science-fiction world) and take control over many of that character's actions. MMORPGs are distinguished from single-player or small multi-player online RPGs by the number of players, and by the game's persistent world (usually hosted by the game's publisher), which continues to exist and evolve while the player is offline and away from the game." [Massively multiplayer online role-playing game. Wikipedia]
This ERD example was redrawn using the ConceptDraw PRO diagramming and vector drawing software from the Wikipedia file: ER Diagram MMORPG.png. [ wiki/ File:ER_ Diagram_ MMORPG.png]
This file is licensed under the Creative Commons Attribution-Share Alike 3.0 Unported license. [ licenses/ by-sa/ 3.0/ deed.en]
This Chen's ERD example is included in the Entity-Relationship Diagram (ERD) solution from the Software Development area of ConceptDraw Solution Park.
Chen's ERD
Chen's ERD, weak key attribute, weak entity, relationship, multivalue attribute, key attribute, identifying relationship, entity, derived attribute, attribute,

entity-relationship diagram, ER-diagram, database ERD Entity-Relationship Diagram (ERD)

entity-relationship diagram, ER-diagram, database ERD
Entity-Relationship Diagram (ERD) solution extends ConceptDraw PRO software with templates, samples and libraries of vector stencils from drawing the ER-diagrams by Chen's and crow’s foot notations.

How to Create an Entity-Relationship Diagram Using ConceptDraw Solution Park

An entity-relationship diagram (ERD)is used in a database modeling process. ERD diagram shows a graphical representation of objects or concepts within an information system and their relationships.The ability to  describe a database using the Entity-Relationship model is delivered by the ConceptDraw ERD solution.
"Crow's Foot notation is used in Barker's Notation, SSADM and Information Engineering. Crow's Foot diagrams represent entities as boxes, and relationships as lines between the boxes. Different shapes at the ends of these lines represent the cardinality of the relationship." [Entity–relationship model. Wikipedia]
The vector stencils library ERD, crow's foot notation contains 17 symbols for creating the ER-diagrams using the ConceptDraw PRO diagramming nd vector drawing software.
The example"Design elements - ERD solution (crow's foot notation)" is included in the Entity-Relationship Diagram (ERD) solution from the Software Development area of ConceptDraw Solution Park.
Crow's foot ERD
Crow's foot ERD, entity,

Data structure diagram with ConceptDraw PRO

Data structure diagram (DSD) is intended for description of conceptual models of data (concepts and connections between them) in the graphic format for more obviousness. Data structure diagram includes entities description, connections between them and obligatory conditions and requirements which connect them. Create Data structure diagram with ConceptDraw PRO.

How to Create an ERD Diagram

ERD (entity relationship diagram) is used to show the logical structure of databases. It represents the interrelationships between components of database (entities). Entity relationship diagrams are a widely used in software engineering. Using ERD software engineers can control the every aspect of database development. ER diagram can be used as guide for testing and communicating before the release of software product. ERD displays data as entities that are connected with connections that show the relationships between entities. There is some ERD notations used by data bases developers for representing the relationships between the data objects. ConceptDraw PRO and its ERD solution allow you to build ERD diagram of any notation.

IDEF1 standard

Use Case Diagrams technology. Using visual graphical objects IDEF1 standard allows to model information interrelations.