Anyone Have an ERD Symbols Quick Reference?


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ERD drawing becomes easier with predesigned entity relationship symbols, work flow shapes, entity relationship stencils. We are glad to offer you all variety of ERD symbols you may need for ERDs design, they are packed into libraries and templates from Entity-Relationship Diagram (ERD) Solution for ConceptDraw PRO diagramming and vector drawing software.

But anyone have an ERD symbols quick reference? Detailed reference information for them is represented at the tables below on this page.

Sample 1. Anyone Have an ERD Symbols Quick Reference?

There are two notations used for ERDs: Chen and Crow's Foot. Variety of symbols offered by two libraries of Entity-Relationship Diagram (ERD) Solution covers both these notations.


Crow’s Foot notation ERD symbols

Symbol Meaning
Relationships (Cardinality and Modality)
ERD symbol -  Entity relationship Zero or More
ERD symbol -  Entity relationship One or More
ERD symbol -  Entity relationship One and only One
ERD symbol -  Entity relationship Zero or One
Many - to - One
ERD Symbols - Relationship Many to One a one through many notation on one side of a relationship and a one and only one on the other
ERD Symbols - Relationship Many to One a zero through many notation on one side of a relationship and a one and only one on the other
ERD Symbols - Relationship Many to One a one through many notation on one side of a relationship and a zero or one notation on the other
ERD Symbols - Relationship Many to One a zero through many notation on one side of a relationship and a zero or one notation on the other
Many - to - Many
ERD Symbols - Relationship Many to Many a zero through many on both sides of a relationship
ERD Symbols - Relationship Many to Many a one through many on both sides of a relationship
ERD Symbols - Relationship Many to Many a zero through many on one side and a one through many on the other
ERD Symbols - Relationship Many to Many a one and only one notation on one side of a relationship and a zero or one on the other
ERD Symbols - Relationship Many to Many a one and only one notation on both sides


Chen's notation ERD symbols

Symbol Shape Name Symbol Description
Entities
ERD Symbols and Meaning - Entity Entity An entity is represented by a rectangle which contains the entity’s name.
ERD Symbols and Meaning - Weak Entity Weak Entity An entity that cannot be uniquely identified by its attributes alone. The existence of a weak entity is dependent upon another entity called the owner entity. The weak entity’s identifier is a combination of the identifier of the owner entity and the partial key of the weak entity.
ERD Symbols and Meaning - Associative Entity Associative Entity An entity used in a many-to-many relationship (represents an extra table). All relationships for the associative entity should be many
Attributes
ERD Symbols and Meaning - Attribute Attribute In the Chen notation, each attribute is represented by an oval containing atributte’s name
ERD Symbols and Meaning - Key attribute Key attribute An attribute that uniquely identifies a particular entity. The name of a key attribute is underscored.
ERD Symbols and Meaning - Multivalue attribute Multivalued attribute An attribute that can have many values (there are many distinct values entered for it in the same column of the table). Multivalued attribute is depicted by a dual oval.
ERD Symbols and Meaning - Derived attribute Derived attribute An attribute whose value is calculated (derived) from other attributes. The derived attribute may or may not be physically stored in the database. In the Chen notation, this attribute is represented by dashed oval.
Relationships
ERD Symbols and Meaning - Relationship Strong relationship A relationship where entity is existence-independent of other entities, and PK of Child doesn’t contain PK component of Parent Entity. A strong relationship is represented by a single rhombus
ERD Symbols and Meaning - Identifying Relationship Weak (identifying) relationship A relationship where Child entity is existence-dependent on parent, and PK of Child Entity contains PK component of Parent Entity. This relationship is represented by a double rhombus.

Collection of samples and examples included to Entity-Relationship Diagram (ERD) solution and represented at ConceptDraw Solution Browser is an excellent illustration of the ease of application of ready-to-use objects for designing Entity-Relationship diagrams and models.

ERD Example

Example 2. ERD Example

This sample was created in ConceptDraw PRO using the vector objects from the ERD Chen's Notation library of Entity-Relationship Diagram (ERD) Solution and illustrates the Entity Relationship Diagram. An experienced user spent 15 minutes creating this sample.

Use the Entity-Relationship Diagram (ERD) Solution for ConceptDraw PRO software to create your own professional looking ER Diagrams quick, easy and effective.

All source documents are vector graphic documents. They are available for reviewing, modifying, or converting to a variety of formats (PDF file, MS PowerPoint, MS Visio XML, and many other graphic formats) from the ConceptDraw Solution Browser v3. The Entity-Relationship Diagram (ERD) Solution is available for all ConceptDraw PRO v9.5 or later users.












Use Product:

  • Software Development Tool
  • Diagram Software
  • Technical Diagramming Tool
  • Business Diagramming Tool
  • Professional Business Graphics Tool
  • ERD Diagrams Software
  • Cross Platform Compatibility


Use Solution:

Entity-Relationship Diagram (ERD)
  • Describing a database
  • Illustrate the logical structure of databases
  • Chen's notation
  • Crow’s Foot notation
  • Quick-Start ERD templates and samples
  • Entity Relationship Diagram examples
  • ERD vector elements
  • Import/Export Microsoft Visio™
  • Export to graphics files and PDF
  • Export to PPT™
  • Make Presentation


See also samples:


Compatibility: Apple® OS X 10.10 or later
Microsoft® Windows® 7/8.1/10

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