The semantic modeling method nowadays is successfully applied in database structure design. It is effective method of modeling the data structures, which is based on the meaning of these data. As a tool of semantic modeling, there are used different types of Entity-Relationship Diagrams. Entity Relationship Diagram (ERD) is applied to visually and clearly represent a structure of a business database. The main components of ERDs are: entity, relation and attributes. An entity is a class of similar objects in the model, each entity is depicted in the form of rectangle and has the name expressed by a noun. Relation is shown in the form of non-directional line that connects two entities. There are several notation styles used for ERDs: information engineering style, Chen style, Bachman style, Martin Style.
The Entity Relationship Diagram symbols used for professional ERD drawing are predesigned by professionals and collected in the libraries of the Entity-Relationship Diagram (ERD) solution for ConceptDraw PRO software. Read more
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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. Read more
Data modeling is actively applied in analysis and uses wide set of methods for description the data requirements in a system. One of the most popular and well-known is the ERD method of database modeling.
The best ERD tool for the Mac and Windows is ConceptDraw PRO software extended with the Entity-Relationship Diagram (ERD) solution from the Software Development Area for ConceptDraw Solution Park, which is sharpened for professional ERD drawing and data modeling with Entity Relationship Diagram. Read more
ConceptDraw PRO diagramming and vector drawing software offers the Entity-Relationship Diagram (ERD) Solution from the Software Development Area for ConceptDraw Solution Park. How many examples contains the Entity-Relationship Diagram (ERD) Solution! All Entity Relationship Diagram examples were designed and saved for ConceptDraw PRO users. Now they are available from ConceptDraw STORE. Read more
Creation of Entity-Relationship (ER) model is a visual representation the structure of a business database, where data equates to entities or objects, which are linked by defined relationships expressing dependencies and requirements. By the nature, the ER model is an abstract visualization, a first step in design process towards creating a logical and functional database.
ConceptDraw PRO professional software gives the ability to effectively describe a database using the Entity-Relationship model. Included to ConceptDraw Solution Park, the Entity-Relationship Diagram (ERD) solution contains the set of predesigned vector icons advocated by Chen's and Crow’s Foot notations that both can be used for data modeling and describing a database. Entity-Relationship Diagram (ERD) solution includes also helpful templates and incredibly large collection of varied Entity Relationship Diagram examples and samples offered at ConceptDraw STORE. Each of them can be used to develop your own model of a database of arbitrary complexity. Read more
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Data Flow Diagram (DFD) is a methodology of graphical structural analysis and information systems design, which describes the sources external in respect to the system, recipients of data, logical functions, data flows and data stores that are accessed. DFDs allow to identify relationships between various system's components and are effectively used in business analysis and information systems analysis. They are useful for system’s high-level details modeling, to show how the input data are transformed to output results via the sequence of functional transformations. For description of DFD diagrams are uses two notations — Yourdon and Gane-Sarson, which differ in syntax.
Online Store DFD example illustrates the Data Flow Diagram for online store, the interactions between Customers, Visitors, Sellers, depicts User databases and the flows of Website Information. ConceptDraw PRO enhanced with Data Flow Diagrams solution lets you to draw clear and simple example of DFD for Online Store using special libraries of predesigned DFD symbols. Read more
Entity-Relationship model gives the possibility to visually describe a database using the components of ER Diagram, entity relationship stencils, relationship symbols, work flow shapes. ER-diagram lets represent the data or entities, attributes of these entities and relationships between them, using standardized Crow’s Foot notation icons or Chen’s notation icons. An entity is an object of the real world, it can exist independently and has the instances which differ in attribute values (properties). The attributes give an unambiguous (uniquely) identification for the instance and are called the primary key, this key can be composite and combine several attributes.
ConceptDraw PRO is a professional software available with Entity-Relationship Diagram (ERD) solution from Software Development area that lets create ERDs for various database systems, using Crow’s Foot and Chen’s notations. It is invaluable tool for software engineers and developers, it supports ODBC-compatible databases (Oracle, MySQL, MS Access, MS SQL, InterBase, Firebird and others). Read more
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Entity-Relationship Diagram (ERD) is applied for detailed description of structures and high-level (conceptual) design databases using the Chen's and Crow's Foot notations. An ERD represents a diagram constructed mainly of rectangular blocks (for entities, data) linked with relationships. The links between the blocks are used to describe relations between the entities. There are three types of relationships: one-to-one, one-to-many, and many-to-many.
Use the specialized ERD software - ConceptDraw PRO to create the Entity-Relationship Diagrams (ERDs) of any degree of complexity with Chen's and Crow's Foot notations. Draw them easily applying the powerful built-in tools and libraries of predesigned ERD vector objects from Entity-Relationship Diagram (ERD) solution from the Software Development area of ConceptDraw Solution Park. You can also start with one of ready template or sample included to this solution. Designing the ERDs in ConceptDraw PRO you can easy move the objects within a diagram with saving the relationships between them. Read more
The information system manages the flow of data introduced into the system. To graphically represent and document the flow of data through some information system is used a Data Flow Diagram (DFD). DFD is a way to visualize the flow of data or data processing, to clearly demonstrate what type of data or information is transferred, where they come from and where are sent. It lets to create an overview of the system, to depict the major steps, and effectively model the processes. DFDs are helpful for analyzing and modifying the business systems. Traditionally are used two notations for DFDs creation - Yourdon-Coad and Gane-Sarson.
ConceptDraw PRO software offers a special Data Flow Diagrams solution from Software Development area, which enables to quickly and simply create professional Data Flow Diagrams including the data storage, data flows, external entities, functional transforms, control transforms and signals. Use the offered templates, samples and extensive range of libraries to design your own Data Flow Diagrams in minutes. Read more
ER-model is a data model which lets describe the conceptual schemes in a specific subject area. It can help to highlight the key entities and specify relationships that can be established between these entities. During the database design, it is realized the transformation of ER model into certain database scheme based on the chosen data model (relational, object, network, etc.). There are used two notations for ERDs: Crow's Foot and Chen's.
Crow's Foot notation proposed by Gordon Everest represents the entity by rectangle containing its name (name must be unique within this model), and relation - by the line which links two entities involved in relationship. The relationship's plurality is graphically indicated by a "plug" on the end of the link, the optionality - by a circle. Entity-Relationship Diagrams based on Crow's Foot notation can be easily drawn using the ConceptDraw PRO. Extended with Entity-Relationship Diagram (ERD) solution, it is the best ERD diagrams software with powerful tools and ready design elements for Crow's Foot and Chen notations. Read more