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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'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,

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)
The vector stencils library "ERD, Chen's notation" contains 13 ERD elements.
Use it for drawing ER-diagrams using Chen's notation in the ConceptDraw PRO diagramming and vector drawing software extended with the Entity-Relationship Diagram (ERD) solution from the Software Development area of ConceptDraw Solution Park.
Entity
Entity, entity,
Weak entity
Weak entity, weak entity,
Relationship
Relationship, relationship,
Identifying Relationship
Identifying Relationship, identifying relationship,
Associative Entity
Associative Entity, associative entity,
Participation
Participation,
Optional participation
Optional participation,
Recursive Relationship
Recursive Relationship,
Attribute
Attribute, attribute,
Key attribute
Key attribute, key attribute,
Weak key attribute
Weak key attribute, weak key attribute,
Derived attribute
Derived attribute, derived attribute,
Multivalue attribute
Multivalue attribute, multivalue attribute,
The vector stencils library "ERD, Chen's notation" contains 13 ERD elements.
Use it for drawing ER-diagrams using Chen's notation in the ConceptDraw PRO diagramming and vector drawing software extended with the Entity-Relationship Diagram (ERD) solution from the Software Development area of ConceptDraw Solution Park.
Entity
Entity, entity,
Weak entity
Weak entity, weak entity,
Relationship
Relationship, relationship,
Identifying Relationship
Identifying Relationship, identifying relationship,
Associative Entity
Associative Entity, associative entity,
Participation
Participation,
Optional participation
Optional participation,
Recursive Relationship
Recursive Relationship,
Attribute
Attribute, attribute,
Key attribute
Key attribute, key attribute,
Weak key attribute
Weak key attribute, weak key attribute,
Derived attribute
Derived attribute, derived attribute,
Multivalue attribute
Multivalue attribute, multivalue attribute,
"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,

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.
"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,

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.
The vector stencils library "ERD, Chen's notation" contains 13 ERD elements.
Use it for drawing ER-diagrams using Chen's notation in the ConceptDraw PRO diagramming and vector drawing software extended with the Entity-Relationship Diagram (ERD) solution from the Software Development area of ConceptDraw Solution Park.
Entity
Entity, entity,
Weak entity
Weak entity, weak entity,
Relationship
Relationship, relationship,
Identifying Relationship
Identifying Relationship, identifying relationship,
Associative Entity
Associative Entity, associative entity,
Participation
Participation,
Optional participation
Optional participation,
Recursive Relationship
Recursive Relationship,
Attribute
Attribute, attribute,
Key attribute
Key attribute, key attribute,
Weak key attribute
Weak key attribute, weak key attribute,
Derived attribute
Derived attribute, derived attribute,
Multivalue attribute
Multivalue attribute, multivalue attribute,