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Entity Relationship Diagram Symbols

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 DIAGRAM software.

ERD Symbols and Meanings

Entity Relationship Diagram (ERD) is a popular software engineering tool for database modeling and illustration the logical structure of databases, which uses one of two notations - Chen's or Crow’s Foot. Crow's foot notation is effective when used in software engineering, information engineering, structured systems analysis and design. Each of these notations applies its own set of ERD symbols. Crow's foot diagrams use boxes to represent entities and lines between these boxes to show relationships. Varied shapes at the ends of lines depict the cardinality of a given relationship. Chen's ERD notation is more detailed way to represent entities and relationships. ConceptDraw DIAGRAM application enhanced with all-inclusive Entity-Relationship Diagram (ERD) solution allows design professional ER diagrams with Chen's or Crow’s Foot notation on your choice. It contains the full set of ready-to-use standardized ERD symbols and meanings helpful for quickly drawing, collection of predesigned ERD samples, examples and templates. ConceptDraw Pro is a great alternative to Visio for Mac users as it offers more features and can easily handle the most demanding professional needs.
How to Build an Entity Relationship Diagram (ERD)
How to Build an Entity Relationship Diagram (ERD)

Chen ERD Diagram

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.

Components of ER Diagram

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 DIAGRAM 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).

Data structure diagram with ConceptDraw DIAGRAM

Data structure diagram (DSD) is intended for description of conceptual models of data (concepts and connections between them) in the graphic format for more obviousness. Data structure diagram includes entities description, connections between them and obligatory conditions and requirements which connect them. Create Data structure diagram with ConceptDraw DIAGRAM.

ConceptDraw DIAGRAM Database Modeling Software

ConceptDraw DIAGRAM is a very easy-to-use and intuitive database design tool which can save you hundreds of work hours. See database diagram samples created with ConceptDraw DIAGRAM database modeling database diagram software.

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 DIAGRAM diagramming and vector drawing software. The Entity-Relationship Diagrams (ERD) solution is contained in the Software Development area of ConceptDraw Solution Park.
"Crow's Foot notation is used in Barker's Notation, SSADM and Information Engineering. Crow's Foot diagrams represent entities as boxes, and relationships as lines between the boxes. Different shapes at the ends of these lines represent the cardinality of the relationship." [Entity–relationship model. Wikipedia]
The vector stencils library ERD, crow's foot notation contains 18 symbols for creating the ER-diagrams using the ConceptDraw PRO diagramming nd vector drawing software.
The example"Design elements - ERD solution (crow's foot notation)" is included in the Entity-Relationship Diagram (ERD) solution from the Software Development area of ConceptDraw Solution Park.
Crow's foot ERD
Crow's foot ERD, entity,

Database Flowchart Symbols

Data base diagrams describes inter-related data and tables. It describes roles and relationships, internal and external dependencies, data exchange conventions and structures of knowledge domain. ConceptDraw Software provides number of data-base chart libraries including major 49 vector symbols. Use these DFD flowchart symbol libraries to design data-base structure and models, use it to design data base process-oriented models, or simple data-oriented models. The are special drawing tools for making data flowcharts, data process diagrams, structured analysis diagrams, and information flow diagrams.
"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,
"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,

Software and Database Design with ConceptDraw DIAGRAM

Unified Modeling Language (abbr. UML) is a modeling language used by software developers and software engineers for developing diagrams, expressive modeling, visualization, construction, specification, and documentation an information about software-intensive systems. There are used many types of UML diagrams, joined in main groups, each of them has its own functional abilities and applications: Behaviour diagrams illustrate the functionality of software systems, Structuring diagrams depict a structure of objects at the systems, Interaction diagrams show the flow of control and data among the things in a modeling system. UML has a lot of practical applications in varied areas, among them software development, hardware design, banking and financial services, telecommunication, science, research, enterprise information system, distributed Web-based services, user interfaces for web applications, medical electronics, patient healthcare systems, etc. ConceptDraw DIAGRAM extended with Rapid UML solution is a perfect tool for UML diagramming.

Amazon Web Services, AWS, Amazon cloud AWS Architecture Diagrams

Amazon Web Services, AWS, Amazon cloud
AWS Architecture Diagrams with powerful drawing tools and numerous predesigned Amazon icons and AWS simple icons is the best for creation the AWS Architecture Diagrams, describing the use of Amazon Web Services or Amazon Cloud Services, their application for development and implementation the systems running on the AWS infrastructure. The multifarious samples give you the good understanding of AWS platform, its structure, services, resources and features, wide opportunities, advantages and benefits from their use; solution’s templates are essential and helpful when designing, description and implementing the AWS infrastructure-based systems. Use them in technical documentation, advertising and marketing materials, in specifications, presentation slides, whitepapers, datasheets, posters, etc.