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.

Chen ERD Diagram

The vector stencils library Chen ERD from the solution Entity-Relationship Diagrams (ERD) contains specific symbols of the Chen ERD notation including entity symbols and relationship 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.

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).

Software and Database Design with ConceptDraw DIAGRAM

Unified Modeling Language (abbr. UML) is a modeling language used by software developers and software engineers for developing diagrams, expressive modeling, visualization, construction, specification, and documentation an information about software-intensive systems. There are used many types of UML diagrams, joined in main groups, each of them has its own functional abilities and applications: Behaviour diagrams illustrate the functionality of software systems, Structuring diagrams depict a structure of objects at the systems, Interaction diagrams show the flow of control and data among the things in a modeling system. UML has a lot of practical applications in varied areas, among them software development, hardware design, banking and financial services, telecommunication, science, research, enterprise information system, distributed Web-based services, user interfaces for web applications, medical electronics, patient healthcare systems, etc. ConceptDraw DIAGRAM extended with Rapid UML solution is a perfect tool for UML diagramming.