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 - 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.

UML Notation

Unified Modeling Language (UML) is an open standard, the language of graphic description used for modeling objects in a field of software development and software engineering. It was created for definition, specification, visualization, designing and documenting software systems, as a unification of three object-oriented technologies Booch, OMT and OOSE, and uses the defined graphic notation for creating the visual models of object-oriented software systems. Description of UML consists of two parts, interactive and supplementing each other: UML semantics, which represents a certain metamodel, defines the abstract syntax and semantics of terms of object modeling with UML, and UML notation that is a graphic notation for visual representation of UML semantics. The powerful tools of the Rapid UML solution included to ConceptDraw Solution Park make the ConceptDraw DIAGRAM diagramming and vector drawing software the best for easy applying the UML notation when creating the visual models of object-oriented software systems and designing different kinds of UML diagrams.