Entity-Relationship Diagram (ERD)

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.

Entity Relationship Diagram Examples

Creation of Entity-Relationship (ER) model is a visual representation the structure of a business database, where data equates to entities or objects, which are linked by defined relationships expressing dependencies and requirements. By the nature, the ER model is an abstract visualization, a first step in design process towards creating a logical and functional database. ConceptDraw DIAGRAM professional software gives the ability to effectively describe a database using the Entity-Relationship model. Included to ConceptDraw Solution Park, the Entity-Relationship Diagram (ERD) solution contains the set of predesigned vector icons advocated by Chen's and Crow’s Foot notations that both can be used for data modeling and describing a database. Entity-Relationship Diagram (ERD) solution includes also helpful templates and incredibly large collection of varied Entity Relationship Diagram examples and samples offered at ConceptDraw STORE. Each of them can be used to develop your own model of a database of arbitrary complexity.

Entity Relationship Diagram Software Engineering

Entity Relationship Diagram (aka ER Diagram, E-R Diagram, ERD) is a time-tested and widespread software development and software engineering method for data modeling, illustrating the logical structure of databases and system design. For ERDs construction are used three basic elements: entities, attributes, and relationships. Chen's notation for ERD supposes the use of rectangles (boxes) to represent entities and diamonds to depict relationships between first-class objects. This notation is popular when creating conceptual data models of information systems. Another standardized notation for ER diagrams is Crow's foot notation. ConceptDraw DIAGRAM as a powerful Entity Relationship Diagram software engineering provides the tools of Entity-Relationship Diagram (ERD) solution from Software Development area of ConceptDraw Solution Park for instantly describing databases using ERDs of Crow’s Foot and Chen’s notations. Use the predesigned vector elements for both these notations from 2 libraries included to Entity-Relationship Diagram (ERD) solution.

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.

Data Modeling with Entity Relationship Diagram

Data modeling is actively applied in analysis and uses wide set of methods for description the data requirements in a system. One of the most popular and well-known is the ERD method of database modeling. The best ERD tool for the Mac and Windows is ConceptDraw DIAGRAM software extended with the Entity-Relationship Diagram (ERD) solution from the Software Development Area for ConceptDraw Solution Park, which is sharpened for professional ERD drawing and data modeling with Entity Relationship Diagram.

Entity Relationship Diagram - ERD - Software for Design Crows Foot ER Diagrams

ER-model is a data model which lets describe the conceptual schemes in a specific subject area. It can help to highlight the key entities and specify relationships that can be established between these entities. During the database design, it is realized the transformation of ER model into certain database scheme based on the chosen data model (relational, object, network, etc.). There are used two notations for ERDs: Crow's Foot and Chen's. Crow's Foot notation proposed by Gordon Everest represents the entity by rectangle containing its name (name must be unique within this model), and relation - by the line which links two entities involved in relationship. The relationship's plurality is graphically indicated by a "plug" on the end of the link, the optionality - by a circle. Entity-Relationship Diagrams based on Crow's Foot notation can be easily drawn using the ConceptDraw DIAGRAM. Extended with Entity-Relationship Diagram (ERD) solution, it is the best ERD diagrams software with powerful tools and ready design elements for Crow's Foot and Chen notations.

ERD Symbols and Meanings

Entity Relationship Diagram (ERD) is a popular software engineering tool for database modeling and illustration the logical structure of databases, which uses one of two notations - Chen's or Crow’s Foot. Crow's foot notation is effective when used in software engineering, information engineering, structured systems analysis and design. Each of these notations applies its own set of ERD symbols. Crow's foot diagrams use boxes to represent entities and lines between these boxes to show relationships. Varied shapes at the ends of lines depict the cardinality of a given relationship. Chen's ERD notation is more detailed way to represent entities and relationships. ConceptDraw DIAGRAM application enhanced with all-inclusive Entity-Relationship Diagram (ERD) solution allows design professional ER diagrams with Chen's or Crow’s Foot notation on your choice. It contains the full set of ready-to-use standardized ERD symbols and meanings helpful for quickly drawing, collection of predesigned ERD samples, examples and templates. ConceptDraw Pro is a great alternative to Visio for Mac users as it offers more features and can easily handle the most demanding professional needs.

Entity-Relationship Diagram

Entity Relationship Diagram (ERD) is the world-known way to show the logical structure of databases in visual manner. The best software tool for drawing Entity-Relationship Diagram is ConceptDraw DIAGRAM ector graphics software with Entity-Relationship Diagram (ERD) solution from Software Development area which gives the ability to describe a database using the Entity-Relationship model. The vector graphic diagrams produced using this solution can be successfully used in whitepapers, presentations, datasheets, posters, or any technical materials.

What is Entity-Relationship Diagram

Entity Relationship Diagram (ERD) is an acknowledged method to visualize the logical structure of databases. Using special symbols described in ERD notations you can depict a database of any complexity. The vector graphic ER diagrams produced when using ConceptDraw ERD solution can be used in whitepapers, presentations, datasheets, posters, or any technical materials.