E-R Diagrams

Complexity of databases increases day by day, due to this the Entity relationship models and E-R diagrams become more and more popular, and now are an important part of database design. E-R diagrams allow visually and graphically represent structure and design of databases.

You can use so popular Chen's notation to represent all components of database and their relationships on the ER diagram. This notation was developed and implemented by Peter Chen in 1976. The main components of the E-R diagrams are:

• entities,
• attributes that describe these entities,
• relationships among these entities that describe associations between the data,
• cardinalities that describe the number of relationship participants: one-to-many (1:M), many-to-many (M:N), and one-to-one (1:1).

In a Chen's notation, entities are represented by rectangles on the diagram with the entity names written inside and relationships are represented by diamonds. Another popular type of E-R diagrams is known as Crow's Foot notation that is derived from the Chen's notation.

Example 1. E-R Diagram - Students and teachers

Use of ConceptDraw DIAGRAM for professional ERD drawing includes using the predesigned components of ER diagram, such as entity relationship symbols, work flow shapes, entity relationship stencils. All they are provided for easy use by 2 libraries of Entity-Relationship Diagram (ERD) Solution from the Software Development Area for ConceptDraw Solution Park.

Example 2. ERD Libraries

There is also wide collection of predesigned E-R Diagrams which is represented at ConceptDraw STORE. All E-R Diagrams samples and templates are well thought-out, professionally designed, can be easy changed according to your needs and further successfully used.

Example 3. E-R Diagrams in ConceptDraw DIAGRAM

The following features make ConceptDraw DIAGRAM extended with the Entity-Relationship Diagram (ERD) solution the most effective E-R diagrams design software:

1. You don't need to be an artist to draw professional looking diagrams in a few minutes.
2. Large quantity of ready-to-use vector objects makes drawing your diagrams quick and easy.
3. Extensive collection of pre-designed templates and samples give you a great start for your own diagrams.
4. ConceptDraw DIAGRAM provides you with the possibility to use the grid, rules and guides. You can easily rotate, group, align, and arrange objects, and use different fonts and colors to make your diagram stand out.
5. All ConceptDraw DIAGRAM documents are vector graphic files and are available for reviewing, modifying, and converting to a variety of formats: image, HTML, PDF file, MS PowerPoint Presentation, Adobe Flash, MS Visio.
6. Using ConceptDraw STORE you can navigate through ConceptDraw Solution Park, managing downloads and updates. You can access libraries, templates and samples directly from ConceptDraw STORE.
7. If you have any questions, our support is free of charge and always ready to come to your aid.