Data modeling

Data modeling

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  Data Modeling
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  Data Modeling • Requirementsmodeling includes many sub-stages, one of them being data modeling. • Once a use case exists, one of the stages that follow will be data modeling. • Data modeling, sometimes also called information modeling, is the process of visually representing what data the application or system will use, and how the data will flow.
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  Data Modeling • Thefundamental elements that a data model needs to include and describe are the data objects, more frequently called 'entities', the attributes of those objects/entities, and the relationships between the objects/entities. • The two most widely used are UML (Unified Modeling Language), and ERD (Entity-Relationship Diagrams). • The software engineer defines all the data object that proceeds within the system and the relationship between data objects are identified.
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  Data Modeling
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  Data Object • Thedata object is the representation of composite information. • The composite information means an object has a number of different properties or attribute. • For example, Height is a single value so it is not a valid data object, but dimensions contain the height, the width and depth these are defined as an object. • Data Entity /Object • An entity is something that exists as itself, as a subject or as an object, actually or potentially, concretely or abstractly, physically or not. • Data Attributes Each of the data object has a set of attributes. • Relationship Relationship shows the relationship between data objects and how they are related to each other. • Cardinality Cardinality state the number of events of one object related to the number of events of another object.
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  Cardinality  The cardinalityexpressed as: One to one (1:1) One event of an object is related to one event of another object. For example, one employee has only one ID. One to many (1:N) One event of an object is related to many events. For example, One collage has many departments. Many to many(M:N) Many events of one object are related to many events of another object. For example, many customer place order for many products.
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  Example of PersonObject
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  Example-Online Tuition/course
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  Example-Banking System