ConceptDraw DIAGRAM ER Diagram Tool
The main tool of domain modeling at the stage of conceptual design is the Entity-relationship model, also called ER-model. Modeling domain data structures is based on the usage of graphical tools — ER-diagrams (Entity-Relationship diagrams). Simply put, it is a visual representation of relationships between entities.
The core concepts of ER Diagram are entity, attribute and relationship.
An entity is an object of the real world that can exist independently. An entity has instances which differ in attribute values and allow unambiguous identification. An attribute is a property of the essence. For example, the entity named Book is characterized by attributes such as author, title, price, publishing house, edition, number of pages. Specific books are instances of the book entity. These instances vary in the values of these attributes and are uniquely identified by the attribute "name". Attribute that uniquely identifies the instance of the entity is called the primary key. It may also be a composite key, which is a combination of several attributes.
A very important feature of the entity-relationship model is that it can be represented as a graphical diagram. This greatly facilitates the subject area analysis. There are several notations used to represent entity-relationship elements, like Crow’s foot notation, or Chen notation, and each has its pros and cons.
Example 1. ER Diagram
The entity on the ER-diagram is represented in the form of a rectangle, which indicates its name. Relationship is the interaction between entities, which is characterized by degree which counts how many entities are involved in the relation. The relationship between the two entities is called binary, and the relationship between more than two entities is ternary. Attributes, entities and relationships are connected by straight lines. Relation is shown in the form of a diamond. When creating a diagram, you can follow a few obvious steps. First, you need to identify entities and relationships among them. The following step is to identify the semantic information in the sets of relations (for example, whether a certain set of connections is a 1:n relation). Then you should define relationships cardinalities and determine attributes and their values sets. The final step is to organize the data in the form of entity-relationship connections.
As an example, let’s imagine a database designed for storing information about some bank activities. The bank has affiliates, which are controlled by managers. Customers of the bank have different types of accounts — current, term, demand, deposit, card account. Branches handle these accounts. The described domain will be called Bank. Let’s determine four entities: the Affiliate, the Manager, the Account, the Customer and some relations among them: the Manager controls the Affiliate; the Affiliate handles the Account; the Customer has the Account.
ConceptDraw PRO v5 with Entity-Relationship Diagram (ERD) solution serving as ERD software allows you to visually create Entity Relationship diagrams (ERDs) for various database systems, it supports ODBC-compatible databases (Oracle, MS SQL, InterBase, MySQL, MS Access, Firebird and others). The built-in scripting language allows to connect to ODBC-compatible databases and automatically generate the structure of a database (reverse engineering of the database structure).
Example 2. ConceptDraw ER Diagram Tool
ConceptDraw ER Diagram Tool works across any platform, meaning you never have to worry about compatibility again. ConceptDraw PRO v5 allows you to make Entity-Relationship Diagram (ERD) on PC or macOS operating systems.
When creating an ERD our ERD software considers individual database options such as referential integrity, constraints, domains, triggers, stored procedures, functions, packages, views, sequences, synonyms etc.
ConceptDraw PRO v5 is a very easy-to-use and intuitive database design tool and ER Diagram tool which can save you hundreds hours of work. Entity-Relationship Diagram (ERD) solution contains 2 libraries with 45 predesigned vector graphic elements, collection of professional ERD samples, examples and templates.
ConceptDraw PRO v5 is excellent choice of database designers for modeling, reverse and forward engineering of relational databases. It is not only an excellent tool for ER Diagram, but also the one that allows you to reverse engineer already existing database structures, create detailed HTML, PDF or PPT reports.
Example 3. ER Diagram (ERD)
The ER Diagram samples you see on this page were created in ConceptDraw PRO v5 using the Entity-Relationship Diagram (ERD) Solution. They successfully demonstrate solution's capabilities and professional results you can achieve. An experienced user spent 10 minutes creating every of these samples.
Use the Entity-Relationship Diagram (ERD) Solution for ConceptDraw PRO v5 software to create your own professional looking ER Diagrams quick, easy and effective, and then successfully use them in your scientific or education activity.
All source documents are vector graphic documents. They are available for reviewing, modifying, or converting to a variety of formats (PDF file, MS PowerPoint, MS Visio, and many other graphic formats).
TEN RELATED HOW TO's:
To visualize the relationships between subsets of the universal set you can use Venn diagrams. To construct one, you should divide the plane into a number of cells using n figures. Each figure in the chart represents a single set of, and n is the number of represented sets. Splitting is done in a way that there is one and only one cell for any set of these figures, the points of which belong to all the figures from the set and do not belong to others. The plane on which the figures are represented, is the universal set U. Thus, the point which does not belong to any of the figures, belongs only to U.
Picture: Multi Layer Venn Diagram. Venn Diagram Example
ConceptDraw DIAGRAM 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 DIAGRAM users. Now they are available from ConceptDraw STORE.
Picture: Entity Relationship Diagram Examples
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
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.
Picture: Entity Relationship Diagram Symbols
UML Collaboration Diagram depicts the interactions between objects or parts in terms of sequenced messages and describes both the static structure and dynamic behavior of a system.
Rapid UML solution provides templates, examples and libraries of stencils for quick and easy drawing all the types of system and software engineering diagrams according to UML 2.4 and 1.2 notations.
Picture: UML Collaboration Diagram (UML2.0)
How to Draw ER Diagrams? With Entity-Relationship Diagram (ERD) solution from the Software Development Area for ConceptDraw Solution Park you are able to draw ER diagram with no problem. It includes 45 predesigned icons advocated by popular Chen's and Crow’s Foot notations that can be used when describing an enterprise database.
Picture: How to Draw ER Diagrams
Creating of Entity-Relationship Diagrams (ERDs) is a complex process that requires convenient, automated tools. ConceptDraw DIAGRAM diagramming and vector drawing software offers a powerful ER Diagram Tool - the Entity-Relationship Diagram (ERD) Solution from the Software Development Area.
Picture: ER Diagram Tool
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 DIAGRAM 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.
Picture: Data Modeling with Entity Relationship Diagram
While creating flowcharts and process flow diagrams, you should use special objects to define different statements, so anyone aware of flowcharts can get your scheme right. There is a short and an extended list of basic flowchart symbols and their meaning. Basic flowchart symbols include terminator objects, rectangles for describing steps of a process, diamonds representing appearing conditions and questions and parallelograms to show incoming data.
This diagram gives a general review of the standard symbols that are used when creating flowcharts and process flow diagrams. The practice of using a set of standard flowchart symbols was admitted in order to make flowcharts and other process flow diagrams created by any person properly understandable by other people. The flowchart symbols depict different kinds of actions and phases in a process. The sequence of the actions, and the relationships between them are shown by special lines and arrows. There are a large number of flowchart symbols. Which of them can be used in the particular diagram depends on its type. For instance, some symbols used in data flow diagrams usually are not used in the process flowcharts. Business process system use exactly these flowchart symbols.
Picture: Basic Flowchart Symbols and Meaning