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Entity Relationship Diagram Symbols

The semantic modeling method nowadays is successfully applied in database structure design. It is effective method of modeling the data structures, which is based on the meaning of these data. As a tool of semantic modeling, there are used different types of Entity-Relationship Diagrams. Entity Relationship Diagram (ERD) is applied to visually and clearly represent a structure of a business database. The main components of ERDs are: entity, relation and attributes. An entity is a class of similar objects in the model, each entity is depicted in the form of rectangle and has the name expressed by a noun. Relation is shown in the form of non-directional line that connects two entities. There are several notation styles used for ERDs: information engineering style, Chen style, Bachman style, Martin Style. The Entity Relationship Diagram symbols used for professional ERD drawing are predesigned by professionals and collected in the libraries of the Entity-Relationship Diagram (ERD) solution for ConceptDraw DIAGRAM software.
This entity-relationship diagram (ERD) sample shows an entity-relationship model for a school. It was designed on the base of the Wikimedia Commons file: Entity-Relationship-Modell.svg. [commons.wikimedia.org/ wiki/ File:Entity-Relationship-Modell.svg]
"An entity–relationship model (ER model) describes inter-related things of interest in a specific domain of knowledge. An ER model is composed of entity types (which classify the things of interest) and specifies relationships that can exist between instances of those entity types.
In software engineering an ER model is commonly formed to represent things that a business needs to remember in order to perform business processes. Consequently, the ER model becomes an abstract data model that defines a data or information structure that can be implemented in a database, typically a relational database." [Entity–relationship model. Wikipedia]
The Chen's notation ER-diagram example "Entity-relationship model" was created using ConceptDraw PRO software extended with the Chen Notation solution from the Software Development area of ConceptDraw Solution Park.
Chen's ERD
Chen's ERD, relationship, participation, key attribute, entity, attribute,
Used Solutions

Entity Relationship Diagram - ERD - Software for Design Chen ER Diagrams

The Entity-Relationship Diagram (ERD) solution from ConceptDraw Solution Park extends ConceptDraw DIAGRAM ector graphics and diagramming software with the ability to describe a database using the Entity-Relationship (Chen) model. Use it for design your ERDs and verify that ConceptDraw DIAGRAM offers the best ERD diagrams software tools for design element Chen notation.

ConceptDraw DIAGRAM ER Diagram Tool

Entity-relationship model, also called ER-model, is the main tool of domain modeling on the stage of conceptual design. The modeling of domain data structures is based on the use of graphical tools - Entity-Relationship diagrams (ER-diagrams). The core concepts of ER-Diagram are entity, attribute and relationship. ER-diagram lets visually represent the entities, helps effectively document all properties of designed system and to detail the data storages. To represent the elements at ER-model are commonly used Chen’s notation and Crow’s foot notation, each has its pros and cons. The entity on ER-diagram is represented in the form of rectangle, which specifies its name. An attribute is a property of the entity and relationship is an interaction between the entities. The relationship between two entities is called binary, between more than two entities - ternary. Specific software, such as ConceptDraw DIAGRAM with Entity-Relationship Diagram (ERD) solution from ConceptDraw Solution Park is helpful for easy creation Entity-Relationship Diagrams.

Entity Relationship Diagram Software for Mac

Great part of modern approaches to the database design are based on the use of different versions of ER-models. The important feature of entity-relationship model is that it can be visually represented as a graphical diagram. ER-models and Entity Relationship Diagrams are so popular due to the simplicity and the presentation clarity. The conceptual basis led to their widespread use in CASE-systems, which support automatic design of relational databases. The typical concepts for ER-models are entity, relation and attribute. Relation is a graphically represented association between two entities, that establishes certain rules and all instances of the linked entity types are subject to these rules. In common ER-model this association is always binary. For representing entity-relationship elements, there are used Crow’s foot and Chen notations. ConceptDraw DIAGRAM is a famous Entity Relationship Diagram software for Mac OSX which gives the ability to describe visually the databases with Chen’s and Crow’s Foot notation icons from Entity-Relationship Diagram (ERD) solution.

ER diagram tool for OS X

ER diagram is the most popular database design tool which lets create graphical representations of database tables, their columns and also relationships. As for the Mac users, they are very interested in powerful database diagramming tools and ER diagram tool for OS X to design professional looking E-R Diagrams and ERD drawings. ConceptDraw DIAGRAM software on Mac OS X gives the ability to easy draw ERDs.
This object-role modeling (ORM) diagram sample was designed on the base of the Wikimedia Commons file: Orm modell beispiel.gif. [commons.wikimedia.org/ wiki/ File:Orm_ modell_ beispiel.gif]
"Object-role Modeling (ORM) is a fact-oriented modeling approach for expressing, transforming and querying information at a conceptual level. Unlike Entity-Relationship modeling and Unified Modeling Language class diagramming, fact-oriented modeling is attribute-free, treating all elementary facts as relationships expressed in natural language sentences. For information modeling, ORM graphical notations are typically far more expressive than other notations, and ORM’s attribute-
free nature promotes semantic stability and facilitates natural verbalization." [www.orm.net/ pdf/ ORM2_ TechReport1.pdf]
The object-role model example "Object role modeling example" was designed using ConceptDraw PRO software extended with ORM Diagrams solution from Software Development area of ConceptDraw PRO Solution Park.
ORM diagram
ORM diagram, value, ORM diagrams, object-role modeling, role connector, entity, ORM diagrams, object-role modeling, binary predicate, binary association, binary predicate vertical,
Used Solutions

Business Process Modeling Software for Mac

ConceptDraw DIAGRAM - business process modeling software for mac offers the Business Process Diagram Solution with powerful tools to help you easy represent the business processes and create the business process diagrams based on BPMN 1.2 and BPMN 2.0 standards that allows to create of both simple and complex (nested) models of processes.

Software for Drawing EPC Diagrams

Event-Driven Process chain Diagrams for improvement throughout an organisation. ConceptDraw DIAGRAM - software that reduces the time needed to create a business process model.