This site uses cookies. By continuing to browse the ConceptDraw site you are agreeing to our Use of Site Cookies.

# Design elements - ER diagram (Chen notation)

## Design elements - ER diagram (Chen notation)

"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. Read more
Chen's ERD
Used Solutions

## Databases Access Objects Model with ConceptDraw PRO

ConceptDraw Basic gives the opportunity of interaction with any ODBC-compatible databases. For this the Database Access Objects Model is provided. All calls to the database are made by certain methods of objects of this model. Read more

## Flowcharts

The Flowcharts Solution for ConceptDraw PRO v10 is a comprehensive set of examples and samples in several different color themes for professionals that need to graphically represent a process. Solution value is added by basic flow chart template and shapes' library of Flowchart notation. ConceptDraw PRO flow chart creator lets one depict a processes of any complexity and length, as well design of the flowchart either vertically or horizontally. Read more

## Spatial Infographics

Spatial infographics solution extends ConceptDraw PRO software with infographic samples, map templates and vector stencils libraries with design elements for drawing spatial information graphics. Read more