Chen ERD Diagram

An entity–relationship model is also known as “ER model”. This model describes the inter related things of interest in a limited domain of knowledge and it is composed of the entity types, which all classify the so-called “things of interest”. The model specifies all of the relationships that can exist between instances of the entity types.

An ER model is very commonly used in software engineering, being formed in order to represent the things that some business needs to remember. It is being done in order to perform any needed business process, making the ER model to become an abstract “data model” for a reason of it defining a data structure, which can be implemented in a database (also known as a “relational database”).

Entity–relationship modelling was originally developed for a purpose of using it in a database design in 1976 by Peter Chen. Some other ER-modellers insist of showing the subtype entities connected by the generalization as well as specialization relationships, so ER-model can be used also in the specification of the domain-specific ontologies.

Such entity–relationship model is expected to be a result of the analysis, conducting systematically. This analysis is usually being conducted for a reason of defining as well as describing what is important in order to process in an area of the certain business. Such model does not define any business process, but presents a business data schema in a way of a graphical form. The ER model can be drawn in a graphical form in a way of boxes, which represent entities, connected by lines, which represent relationships, expressing the associations as well as dependencies between those entities.

The mentioned entities may be characterized not only by relationships but by the additional properties (or attributes), including the identifiers known as the "primary keys". The diagrams created in order to represent the needed attributes and entities, as well as any relationships may be called “entity-attribute-relationship diagrams”, or “entity-relationship models” (which is not as common).

A database is known to be the one implementing an ER model. Once there is a simple relational database implementation, each of the existing rows of the table each represents one instance of an entity type. At the very same circumstances, each of the fields mentioned in a table represents some particular attribute type. Once the “relational database” is being discussed, then any relationships between entities are implemented in a way of storing the primary keys of each of the entities.

There are a few kinds of data models, main of which are “conceptual”, “logical” and “physical”. Within the “conceptual” model (which is the highest level possible of any ER model) there is the least granular detail, which establishes the overall scope of what has to be included within the model set itself. Such “conceptual ER model” is meant to define the master reference data entities which are commonly used by any organization, which is involved in the process. This model can also be used as the foundation for one or more than one logical data models and the purpose of having it is to establish the so-called “structural metadata” between the set of the different logical ER models. Do not forget also that this ER model can be used for forming the commonality relationships between the similar models as a basis for the further data model integration.

Another type of the ER models is the “logical” one. This model does not require a conceptual ER-model and it contains more details than the first mentioned one (see above). Additionally, both transactional and operational data entities can be defined to the master data entities. The details of each of the data entities can be developed in this case and the relationships between the data entities can be established no problem. This logical ER model is independent in its development within the so-called specific “database management system”, into which this model can be implemented.

And the last type of the ER models is a “physical” one, being developed from each of the logical ER models. This physical model is usually developed in order to become an instantiated as a “database”. Each of such models must contain enough details in order to produce a database. This last model is being instantiated in the “structural metadata” of a database management system in a way of the relational database objects, for example: database indexes, database tables and so on, as so-called “unique key indexes”. The physical ER model can also be used for designing any needed modifications for the relational database objects and for maintaining the structural metadata of the database.

Once again, “ERD”, or “entity relationship diagram”, is the one being very simple to create in case you know what to start from and how to implement your plans of creating. It would be much better if you had experience in making any similar diagrams before. But once you do not have enough of the experience in making the needed diagrams, including the ER one, then the examples and templates, developed by the team of the professionals, may help you a lot, making it possible to finish with the dream drawing in only a couple of hours.

Thus, having ConceptDraw PRO software and the “Entity-Relationship Diagram (ERD) solution”, which contains a large collection of pre-designed examples of “Entity Relationship Diagrams”, as well as samples and templates for the data modelling, can simplify your task and so to make the planned drawing appear in front of you as a great looking and smart diagram. In case you decide to use the mentioned solution full of examples as well as stencil libraries, then you can always download it from ConceptDraw STORE application or from this site.

Entity-Relationship Diagram (ERD) solution

Example 1. Entity-Relationship Diagram (ERD) solution

So getting all needed, you can use the various icons as well as developed elements in order to develop a model of a database of any complexity according to the Chen's notation. The available drawing tools from Entity-Relationship Diagram (ERD) solution can be very useful for all of our clients, including you. This solution extends ConceptDraw PRO with 2 libraries containing 45 objects advocated by Chen's and Crow’s Foot notations: so helpful while describing any database needed.

Use the Entity-Relationship Diagrams (ERD) solution to draw data model diagrams for your business documents, presentations and websites.

Chen ERD Diagram - Database of a Surgeon

Example 2. Chen ERD Diagram - Database of a Surgeon

The example above illustrates an entity with its' attributes. A surgeon is an entity, and information about him such as name or address is shown as attribute.











Related Solution:

TEN RELATED HOW TO's:

Design Element: Chen for Entity Relationship Diagram - ERD

It is very difficult to get into database model idea without any examples. To create one, you can use Chen’s notation for Entity Relationship Diagrams (ERD) and try to see all the peculiarities yourself. This notation describes entities and relations as basic geometric shapes like rectangles and diamonds. Chen notation for Entity-relationship diagrams is used for designing relational databases. It depicts the database entities as a set of subjects. For example events, people, ideas, etc. All entities has common characteristics (attributes). Any object of the system is identified as the sole and unique. The name of entity should indicate the class or type of the the whole object, not a given example. The connection commonly represents a relationship between entities. Conceptdraw Entity-Relationship Diagrams (ERD) solution provides the libraries with ready-to-use ERD element fitting Chen's notation objects and relationships.ERD. Entity Relationship Diagram, Design Elements - Chen (Win Mac)
Picture: Design Element: Chen for Entity Relationship Diagram - ERD
Related Solution:

Martin ERD Diagram

The vector stencils library Crow's Foot Notation from the solution Entity-Relationship Diagrams (ERD) contains specific symbols of the Crow's foot notation such as relationship symbols and entity symbols for ConceptDraw PRO diagramming and vector drawing software. The Entity-Relationship Diagrams (ERD) solution is contained in the Software Development area of ConceptDraw Solution Park.Martin ERD Diagram - Sales
Picture: Martin ERD Diagram
Related Solution:

Wireframe Tools

A wireframe is a scheme of a future web page. Wireframe illustrates the web page structure, location and size of the main elements, as well as their interaction with the user. With such scheme designer defines the functionality of the page, not its appearance.Wireframe Tools
Picture: Wireframe Tools
Related Solution:

Components of ER Diagram

It is easy to recreate any informational system structure using diagrams. There are three main components of any ER diagram: entity, attribute and relationship. Basing on these three components, one can define other, less used elements, such as weak entity or relationship, derived attribute, recursive relationship etc. This is the set of graphic elements of ERD Chen's notation. This ERD notation is used to represent an entity–relationship models. It involves the set of geometric forms: rectangles - depicting entities, ovals - representing attributes and diamonds depicting relationships assigned for first-class objects, that can have relationships and attributes of their own. Connections are displayed with arrowed lines. It is known that the Chen's ERD notation is used to show a detailed view of entities and relationships. ConceptDraw Entity-Relationship Diagram solution from the Software Development section of Solution Park provides the ability to create ERD of database structure for software development purposes using the Chen’s notation elements.Components of ER Diagram
Picture: Components of ER Diagram
Related Solution:

Entity Relationship Diagram Examples

An abstract representation is usually the first thing you will need while developing a database. To understand the ways that databases are structured, you should look through entity-relationship diagram examples and see the notations features and attributes. With an entity-relationship model you can describe a database of any complexity. This Entity-relationship diagram is a tool for software developers. It enables every element of database to be managed, communicated and tested before release. This ERD was created using symbols advocated by Chen's notation. Because of a linguistic origin of the Chen’s notation, the boxes representing entities could be interpreted as nouns, and the relationships between them are in verb form, shown on a diagram as a diamond.Entity Relationship Diagram Examples
Picture: Entity Relationship Diagram Examples
Related Solution:

Entity-Relationship Diagram (ERD) with ConceptDraw PRO

Database structures are usually described by ER-diagrams which represents entities as boxes with lines-connections between them. You can create any entity-relationship diagram (ERD) by means of ConceptDraw PRO using ready-to-use templates and special libraries containing all the needed symbols and shapes. Creating a model for your database from now on can take just a few minutes. ERD (entity relationship diagram) designed to show the logical structure of databases. It intended to depict the relationships between data components (entities). ERDs are a popular tool for software engineers and architects. Using ERD they can manage the every aspect of database design. Also ERD can be used as guidelines for testing and communications before software release. This diagram represents the file reference system of the WordPress web platform. Because entity relationship diagrams have such a broad application area through the prevalence of database technology, it can be applied for a wide range of users.erd diagram example, er-diagram design software
Picture: Entity-Relationship Diagram (ERD) with ConceptDraw PRO
Related Solution:

Software Diagram Examples and Templates

ConceptDraw Pro is a powerful tool for business and technical diagramming. Software Development area of ConceptDraw Solution Park provides 5 solutions: Data Flow Diagrams, Entity-Relationship Diagram (ERD), Graphic User Interface, IDEFO Diagrams, Rapid UML.UML Class Diagrams
Picture: Software Diagram Examples and Templates
Related Solution:

Entity Relationship Diagram - ERD - Software for Design Chen ER Diagrams

The Entity-Relationship Diagram (ERD) solution from ConceptDraw Solution Park extends ConceptDraw PRO vector graphics and diagramming software with the ability to describe a database using the Entity-Relationship (Chen) model. Use it for design your ERDs and verify that ConceptDraw PRO offers the best ERD diagrams software tools for design element Chen notation.Entity Relationship Diagram Software, Design Elements - Chen (Windows, Macintosh)
Picture: Entity Relationship Diagram - ERD - Software for Design Chen ER Diagrams
Related Solution:

Entity Relationship Diagram Symbols

When we start to speak about databases, we must always mention database structure visualization. One of the most common ways to do it is to create an entity relationship diagram, and to put appropriate symbols on it. It is important either for database projecting and for its' future maintenance. Entity Relationship Diagram describes data elements and their relationships within a database. There are a set of special symbols that depict each element of an entity relationship diagram. Entities - represents some stable components such as supplier, employee, invoice, client, etc. Relation symbols show how the entities interact. Attributes define characteristics of the relationships. Attributes can be one-to-one or many-to-many. Physical symbols is used in the physical models. They represent items such as fields, tables, types and keys. ERD physical symbols are the building material for the database. Notation lines are used to illustrate the relationships. The most common method is Crow’s Feet notation. You can use ConceptDraw Entity-Relationship Diagram (ERD) solution to represent a database using the Entity-Relationship model.Entity Relationship Diagram Symbols
Picture: Entity Relationship Diagram Symbols
Related Solution:

ER Diagram Styles

When creating ER diagrams, you can apply different color ER diagram styles and also notation styles. ConceptDraw PRO enhanced with Entity-Relationship Diagram (ERD) Solution gives the ability to draw visual and attractive ER Diagrams using the style icons from Crow’s Foot notation and Chen's notation professionally designed and offered by ERD Chen's Notation and ERD Crow’s Foot Notation libraries.ER Diagram Styles
Picture: ER Diagram Styles
Related Solution:
1 Diagram Software
Professional business graphics tool for drawing schemes, diagrams and illustrating business documentation
1 Mind Map Software
Excellent tool for Mind Mapping, Planning, Brainstorming, and Building Processes
1 Project Management Software
The full complement of features needed to successfully plan and execute projects, including task and resource management, reporting, and change control