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.

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 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.

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.

Components of ER Diagram

Entity-Relationship model gives the possibility to visually describe a database using the components of ER Diagram, entity relationship stencils, relationship symbols, work flow shapes. ER-diagram lets represent the data or entities, attributes of these entities and relationships between them, using standardized Crow’s Foot notation icons or Chen’s notation icons. An entity is an object of the real world, it can exist independently and has the instances which differ in attribute values (properties). The attributes give an unambiguous (uniquely) identification for the instance and are called the primary key, this key can be composite and combine several attributes. ConceptDraw DIAGRAM is a professional software available with Entity-Relationship Diagram (ERD) solution from Software Development area that lets create ERDs for various database systems, using Crow’s Foot and Chen’s notations. It is invaluable tool for software engineers and developers, it supports ODBC-compatible databases (Oracle, MySQL, MS Access, MS SQL, InterBase, Firebird and others).

Entity-Relationship Diagram (ERD) with ConceptDraw DIAGRAM

Entity-Relationship Diagram (ERD) is applied for detailed description of structures and high-level (conceptual) design databases using the Chen's and Crow's Foot notations. An ERD represents a diagram constructed mainly of rectangular blocks (for entities, data) linked with relationships. The links between the blocks are used to describe relations between the entities. There are three types of relationships: one-to-one, one-to-many, and many-to-many. Use the specialized ERD software - ConceptDraw DIAGRAM to create the Entity-Relationship Diagrams (ERDs) of any degree of complexity with Chen's and Crow's Foot notations. Draw them easily applying the powerful built-in tools and libraries of predesigned ERD vector objects from Entity-Relationship Diagram (ERD) solution from the Software Development area of ConceptDraw Solution Park. You can also start with one of ready template or sample included to this solution. Designing the ERDs in ConceptDraw DIAGRAM you can easy move the objects within a diagram with saving the relationships between them.

Martin ERD Diagram

The vector stencils library Crow's Foot Notation from the solution Entity-Relationship Diagrams (ERD) contains specific symbols of the Crow's foot notation such as relationship symbols and entity symbols for ConceptDraw DIAGRAM diagramming and vector drawing software. The Entity-Relationship Diagrams (ERD) solution is contained in the Software Development area of ConceptDraw Solution Park.

ER Diagram Styles

When creating ER diagrams, you can apply different color ER diagram styles and also notation styles. ConceptDraw DIAGRAM enhanced with Entity-Relationship Diagram (ERD) Solution gives the ability to draw visual and attractive ER Diagrams using the style icons from Crow’s Foot notation and Chen's notation professionally designed and offered by ERD Chen's Notation and ERD Crow’s Foot Notation libraries.

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.