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Entity Relationship Diagram Symbols

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.

ERD Symbols and Meanings

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.
How to Build an Entity Relationship Diagram (ERD)
How to Build an Entity Relationship Diagram (ERD)

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.
How to Build an Entity Relationship Diagram (ERD)
How to Build an Entity Relationship Diagram (ERD)

Notation & Symbols for ERD

The ER diagram is constructed from the specific ERD graphic elements. There are used 2 types of ERD notations: Chen and Crow's Foot. A complete set of work flow shapes, notation & symbols for ERD, entity relationship stencils, included in Entity-Relationship Diagram (ERD) solution for ConceptDraw DIAGRAM software, makes drawing diagrams based on ERD notation as smooth as possible.

Flowchart Components

Flowchart Components
The ConceptDraw Flowchart component includes a set of samples and templates. This geathered as flowchart maker toolbox which focused on drawing flowcharts of any industry standards.
"Chen's notation for entity–relationship modeling uses rectangles to represent entity sets, and diamonds to represent relationships appropriate for first-class objects: they can have attributes and relationships of their own. If an entity set participates in a relationship set, they are connected with a line.
Attributes are drawn as ovals and are connected with a line to exactly one entity or relationship set.
Cardinality constraints are expressed as follows:
- a double line indicates a participation constraint, totality or surjectivity: all entities in the entity set must participate in at least one relationship in the relationship set;
- an arrow from entity set to relationship set indicates a key constraint, i.e. injectivity: each entity of the entity set can participate in at most one relationship in the relationship set;
- a thick line indicates both, i.e. bijectivity: each entity in the entity set is involved in exactly one relationship.
- an underlined name of an attribute indicates that it is a key: two different entities or relationships with this attribute always have different values for this attribute.
Attributes are often omitted as they can clutter up a diagram; other diagram techniques often list entity attributes within the rectangles drawn for entity sets." [Entity–relationship model. Wikipedia]
The vector stencils library ERD, Chen's notation contains 13 symbols for drawing entity-relatinship diagrams using the ConceptDraw PRO diagramming and vector drawing software.
The example "Design elements - ER diagram (Chen notation)" is included in the Entity-Relationship Diagram (ERD) solution from the Software Development area of ConceptDraw Solution Park.
Chen's ERD
Chen's ERD, week key attribute, weak entity, relationship, multivalue attribute, key attribute, identifying relationship, entity, derived attribute, attribute, associative entity,
Used Solutions

ERD Symbols and Meanings

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.
How to Build an Entity Relationship Diagram (ERD)
How to Build an Entity Relationship Diagram (ERD)

Express-G Diagram

The vector stencils library from the solution Information Model Diagrams contains specific data type symbols of the EXPRESS-G notation such as entity data type symbols, simple data type symbols, enumeration data type symbols, defined data type symbols, select data type symbols and specific attribute symbols for ConceptDraw DIAGRAM diagramming and vector drawing software. The Information Model Diagrams solution is contained in the Software Development area of ConceptDraw Solution Park.

Anyone Have an ERD Symbols Quick Reference?

ERD drawing becomes easier with predesigned entity relationship symbols, work flow shapes, entity relationship stencils. All variety of ERD symbols you may need for ERDs design is packed into libraries and templates from Entity-Relationship Diagram (ERD) Solution for ConceptDraw DIAGRAM diagramming and vector drawing software. But anyone have an ERD symbols quick reference? Detailed reference information for them is represented at the tables.

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.
How to Build an Entity Relationship Diagram (ERD)
How to Build an Entity Relationship Diagram (ERD)