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ERD Symbols and Meanings

ERD Symbols and Meanings
Crow's foot notation is used in Barker's Notation, Structured Systems Analysis and Design Method (SSADM) and information engineering. Crow's foot diagrams represent entities as boxes, and relationships as lines between the boxes. Different shapes at the ends of these lines represent the cardinality of the relationship.
The Chen's ERD notation is still used and is considered to present a more detailed way of representing entities and relationships.
To create an ERD, software engineers mainly turn to dedicated drawing software, which contain the full notation resources for their specific database design - ERD symbols and meanings. CS Odessa has released an all-inclusive Entity-Relationship Diagram (ERD) solution for their powerful drawing program, ConceptDraw DIAGRAM.
How to Build an Entity Relationship Diagram (ERD)
How to Build an Entity Relationship Diagram (ERD)
"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

IDEF0 standard with ConceptDraw DIAGRAM

The activity of any organization is more or less branchy network of processes. The description of these processes is a hard technical task which requires definite methodology and standards.
According to the IDEF0 standard any process can be described in the form of a block (Activity Box) which has inputs and outputs. The process consists in transformation of inputs into outputs under the influence of the management and in the presence of necessary resources. Outputs of the given process later on can be either inputs for the next process or resources, or management means.

Network Glossary Definition

The Network Topology Diagram examples was created using ConceptDraw DIAGRAM software with Computer and Networks solution.
Easy to draw network topology diagrams, network mapping and Cisco network topology.
How to Draw a Computer Network
How to Draw a Computer Network

Electrical Symbols — Transformers and Windings

A transformer is an electrical device that transfers electrical energy between two or more circuits through electromagnetic induction. Electromagnetic induction produces an electromotive force within a conductor which is exposed to time varying magnetic fields. Transformers are used to increase or decrease the alternating voltages in electric power applications.


26 libraries of the Electrical Engineering Solution of ConceptDraw DIAGRAM make your electrical diagramming simple, efficient, and effective. You can simply and quickly drop the ready-to-use objects from libraries into your document to create the electrical diagram.

software engineering, data model, data modeling tools, orm Object-Role Modeling (ORM) Diagrams

software engineering, data model, data modeling tools, orm
Object-role Modeling (ORM) Diagram solution with powerful vector diagramming and data modeling tools, large quantity of specially developed samples and examples, and rich variety of vector objects corresponding to common ORM notation, ideally suits for developing the comprehensive, clear and visual Object-role Modeling (ORM) diagrams and schematics, understandable for all interested people from the different fields and business directions, for designing the ORM models, and demonstrating advantages from the use of ORM and its notation. It is intended for software developers and computer engineers, specialists in a field of Object-oriented programming (OOP), database architects, web-application constructors and developers, etc.

Electrical Symbols — Semiconductor

Semiconductors are crystalline or amorphous solids with distinct electrical characteristics. They are of high resistance — higher than typical resistance materials, but still of much lower resistance than insulators. Their resistance decreases as their temperature increases, which is behavior opposite to that of a metal. Finally, their conducting properties may be altered in useful ways by the deliberate, controlled introduction of impurities into the crystal structure, which lowers its resistance but also permits the creation of semiconductor junctions between differently-doped regions of the extrinsic semiconductor crystal. The behavior of charge carriers which include electrons, ions and electron holes at these junctions is the basis of diodes, transistors and all modern electronics.

26 libraries of the Electrical Engineering Solution of ConceptDraw DIAGRAM make your electrical diagramming simple, efficient, and effective. You can simply and quickly drop the ready-to-use objects from libraries into your document to create the electrical diagram.