Martin ERD Diagram
The result of any systematic analysis is expected to be an entity–relationship model, defining and describing what exactly is important in the processes of running any business, although it cannot be used for defining the business processes themselves, but only presenting the business data schemas in a way of a graphical form with help of such graphical objects as boxes representing entities being connected with help of lines representing the relationships and so expressing the dependencies as well as the associations between entities. It is interesting to know that any of the possibly existing entity–relationship models can always be represented in any verbal form.
All the entities within the entity–relationship model can be characterized whether by relationships or by the additional properties representing the “attributes”, including the identifiers known to be called as the "primary keys". All the diagrams created for representing the attributes and entities as well as the relationships can always be called the “entity-attribute-relationship diagrams” and they can always be created in ConceptDraw DIAGRAM software as it is one of the best tools existing for making such drawings.
The implementation of any entity–relationship model is a “database”. Each of the rows of a table in a such relational database implementation can represent only one instance of an entity type. At the same time each of the fields in a table can represent any needed attribute type. In a so called “relational database” a relationship between all the mentioned entities can be implemented in a way of storing the primary key of one entity as well as the so called "foreign key" in the table of different entity.
Usually the data models, such as the entity–relationship ones, are built at two-three levels of abstraction. One of the types of the data models existing and widely used is conceptual one. Being the highest level entity–relationship model, it contains the least granular detail. At the same time, it establishes all the scope of what has to be included in the existing model set. Such models usually define the so called “master reference data entities”. These master reference data entities are very widely and commonly used by different organizations working in so many different fields of the business activity. It is always very useful supporting documenting the data architecture for an organization by developing the conceptual entity–relationship models and so such models are used as the foundations for the logical data models which contain more detail to compare to the conceptual entity–relationship model.
There’s another type of the entity–relationship models which is a “physical ER” one. Such models can be developed from any logical entity–relationship model, being developed for a reason of being instantiated as a “database”. It is well-known that each of the physical entity–relationship models must contain enough details for producing a database. Also, every physical entity–relationship model is always technology dependent when every existing database management system is usually known to be very different from each other. The described physical models are usually instantiated to be created in the structural metadata of some database management system. They are normally created as the relational database objects. Such objects can be database indexes (for example, unique key indexes), database constraints (e.g., a commonality constraint or a foreign key constraint) or database tables.
Any entity–relationship model is usually used for designing different modifications for the relational database objects. It also can be used for maintaining the structural metadata of the needed database. At the same time, the data modelling technique can be used for describing any needed ontology for some particular area of interest. Thus, in case of designing some information system based on a database, the “conceptual data model” can be mapped to a “logical” one (for example the “relational model”). Sometimes both of the phases can be referred to as the so called "physical design."
Once you decide to create any needed Entity-Relationship Diagram with help of a professional and well developed software, then one of the best applications will be the ConceptDraw DIAGRAM diagramming and drawing one. Having this tool means enabling yourself to create the great looking diagrams from a scratch using the basic graphical objects from the stencil libraries in the available to all the ConceptDraw DIAGRAM users which can be found within the application itself. To make it even simpler, you can always make your drawing much quicker if you download another product of CS Odessa known to be ConceptDraw STORE application. This new product enables everyone who uses ConceptDraw DIAGRAM to make the needed drawing much faster as ConceptDraw STORE provides lots of pre-made “solutions”, including the “Entity-Relationship Diagrams (ERD)” one full of the stencil libraries with design elements for making only smart looking diagrams and many other schematics.
Example 1. Entity-Relationship Diagrams (ERD) Solution
Most of the mentioned solutions also include the examples and templates, which were previously created by the developers of the ConceptDraw DIAGRAM and ConceptDraw STORE. Those, who know all about how to make a proper diagram, chart, flowchart, map, plan and many other schemes, developed the professional software and so the application which can be used while working in ConceptDraw DIAGRAM
Example 2. Martin ERD Diagram — Sales
The example below illustrates a data model diagram for a store.
Downloading the ConceptDraw STORE application from this site will enable you to get the Entity-Relationship Diagrams (ERD) solution with two stencil libraries where all 45 stencils can be found and so used from. One of the libraries in called “Design Elements — Chen ERD” and another one as “Design Elements — Crow’s Foot ERD”. Having both stencil libraries, which were mentioned, as well as the pre-made templates of the ER diagrams will help you to ensure yourself in making a great looking ERD within only an hour or even less, depending on how familiar you are with the mentioned products of CS Odessa.
TEN RELATED HOW TO's:
When trying to figure out the nature of the problems occurring within a project, there are many ways to develop such understanding. One of the most common ways to document processes for further improvement is to draw a process flowchart, which depicts the activities of the process arranged in sequential order — this is business process management. ConceptDraw DIAGRAM is business process mapping software with impressive range of productivity features for business process management and classic project management. This business process management software is helpful for many purposes from different payment processes, or manufacturing processes to chemical processes. Business process mapping flowcharts helps clarify the actual workflow of different people engaged in the same process. This samples were made with ConceptDraw DIAGRAM — business process mapping software for flowcharting and used as classic visio alternative because its briefly named "visio for mac" and for windows, this sort of software named the business process management tools.
This flowchart diagram shows a process flow of project management. The diagram that is presented here depicts the project life cycle that is basic for the most of project management methods. Breaking a project into phases allows to track it in the proper manner. Through separation on phases, the total workflow of a project is divided into some foreseeable components, thus making it easier to follow the project status. A project life cycle commonly includes: initiation, definition, design, development and implementation phases. Distinguished method to show parallel and interdependent processes, as well as project life cycle relationships. A flowchart diagram is often used as visual guide to project. For instance, it used by marketing project management software for visualizing stages of marketing activities or as project management workflow tools. Created with ConceptDraw DIAGRAM — business process mapping software which is flowcharting visio alternative or shortly its visio for mac, this sort of software platform often named the business process management tools.
Picture: Process Flowchart
Both Crow’s Foot and Chen’s notations are used to build database models. Each of them has its’ own features, and if you use a proper entity relationship diagram software, you’ll be able to create diagrams of any notation. Database model with clearly defined entities and relationships between them facilitates further work greatly.
This ERD represents the model of Employee Certification Entity. The entity-relationship diagram is a visual instrument of database software development. It is used to structure data and to define the relationships between structured data groups. This ERD was designed with a help of ConceptDraw Entity-Relationship Diagram (ERD) solution. The solution supports the both basic ERD notations used to describe the structure of database: Chen's and Crow’s Foot notations.
Picture: Entity Relationship Software
UML Diagrams Social Networking Sites Project. This sample was created in ConceptDraw DIAGRAM diagramming and vector drawing software using the UML Use Case Diagram library of the Rapid UML Solution from the Software Development area of ConceptDraw Solution Park.
This sample shows the Facebook Socio-health system and is used at the projection and creating of the social networking sites.
Picture: UML Use Case Diagram Example. Social Networking Sites Project
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.
Picture: Entity Relationship Diagram Examples
The vector stencils library Chen ERD from the solution Entity-Relationship Diagrams (ERD) contains specific symbols of the Chen ERD notation including entity symbols and relationship symbols for ConceptDraw DIAGRAM diagramming and vector drawing software. The Entity-Relationship Diagrams (ERD) solution is contained in the Software Development area of ConceptDraw Solution Park.
Picture: Chen ERD Diagram
A database is a data collection, structured into some conceptual model. Two most common approaches of developing data models are UML diagrams and ER-model diagrams. There are several notations of entity-relationship diagram symbols and their meaning is slightly different. Crow’s Foot notation is quite descriptive and easy to understand, meanwhile, the Chen notation is great for conceptual modeling.
An entity relationship diagrams look very simple to a flowcharts. The main difference is the symbols provided by specific ERD notations. There are several models applied in entity-relationship diagrams: conceptual, logical and physical. Creating an entity relationship diagram requires using a specific notation. There are five main components of common ERD notations: Entities, Actions, Attributes, Cardinality and Connections. The two of notations most widely used for creating ERD are Chen notation and Crow foot notation. By the way, the Crow foot notation originates from the Chen notation - it is an adapted version of the Chen notation.
Picture: ERD Symbols and Meanings
When you need to visually represent the structure of relational database, Entity relationship diagram (ERD) is a type of diagram for that case.
Most entity-relationship diagrams can be built with objects from Flowchart solution or ERD Solution which contains inbuilt templates. Follow these steps to create your own custom ERD diagram.
Don't be frightened if it looks complex, ConceptDraw DIAGRAM makes it easy to create an ERD, and hundreds of other diagrams, in minutes.
Picture: Developing Entity Relationship Diagrams
While designing a conceptual data model, you should use appropriate software. For instance, ConceptDraw DIAGRAM is a user-friendly ER diagram tool that has a lot of samples and templates to facilitate your work. A clear entity-relationship diagram helps to define the relations between system’s components.
Software engineering is the section of a computer science engaged to design, realization, and support of complex software products. An ERD is a data modeling method that is widely applied in the software engineering practice. Commonly it is used for developing a structure of a a relational database. An entity relationship diagram is helpful for structuring and organizing databases that can be modeled using a relational structure. An entity relationship diagram is designed to depicts the interrelationships within the sets of entities which are accumulated in the database. Each entity represents a particular component of a data. Thus, ER diagrams depicts the logical structure of databases. ConceptDraw ER Diagrams solution provides software engineers with the professional tool for making entity-relationship diagrams.
Picture: Entity Relationship Diagram Software Engineering