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entity-relationship diagram, ER-diagram, database ERD Entity-Relationship Diagram (ERD)

entity-relationship diagram, ER-diagram, database ERD
Entity-Relationship Diagram (ERD) solution extends ConceptDraw PRO software with templates, samples and libraries of vector stencils from drawing the ER-diagrams by Chen's and crow’s foot notations.

ERD, entity-relationship diagram, ER-diagram, Crow’s Foot Notation Crow’s Foot Notation

ERD, entity-relationship diagram, ER-diagram, Crow’s Foot Notation
Crow’s Foot Notation solution extends ConceptDraw PRO software with powerful drawing tools, samples and library of predesigned vector Crow's Foot notation icons to help you easy describe the databases using the Entity-Relationship models and design professional-looking ER diagrams based on the popular Crow's Foot notation.
HelpDesk

How To Make a Crow's Foot ER Diagram

The Crow's Foot ERD notation is often used in software engineering and database design. The originator of Crow’s Foot notation was Gordon Everest, who offered the idea of how to visually represent the different types of relationships that can exist between objects in an entity relationship diagram (ERD). The Crow’s Foot notation is often used in ER models to how a particular table data can reference data in other tables within a database. The free Crow's Foot Notation solution for ConceptDraw PRO offers a complete vector stencil library containing full standardized symbols of Crow's Foot notation.
"An ER model is an abstract way of describing a database. In the case of a relational database, which stores data in tables, some of the data in these tables point to data in other tables - for instance, your entry in the database could point to several entries for each of the phone numbers that are yours. The ER model would say that you are an entity, and each phone number is an entity, and the relationship between you and the phone numbers is 'has a phone number'. Diagrams created to design these entities and relationships are called entity–relationship diagrams or ER diagrams.
Using the three schema approach to software engineering, there are three levels of ER models that may be developed. ...
Conceptual data model ... is the highest level ER model in that it contains the least granular detail but establishes the overall scope of what is to be included within the model set.
Logical ER model ... contains more detail than the conceptual ER model. In addition to master data entities, operational and transactional data entities are now defined.
The physical ER model is normally developed to be instantiated as a database. Therefore, each physical ER model must contain enough detail to produce a database and each physical ER model is technology dependent since each database management system is somewhat different.
Physical model ... is normally forward engineered to instantiate the structural metadata into a database management system as relational database objects such as database tables, database indexes such as unique key indexes, and database constraints such as a foreign key constraint or a commonality constraint." [Entity–relationship model. Wikipedia]
This crow's foot entity-relationship diagram (ERD) example "Educational data base" was created using 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.
ERD
ERD, entity,