Search results
Results from the WOW.Com Content Network
Class diagram showing generalization between the superclass Person and the two subclasses Student and Professor. The generalization relationship—also known as the inheritance or "is a" relationship—captures the idea of one class, the so-called subclass, being a specialized form of the other (the superclass, super type, or base class). Where ...
The entity–relationship model proposes a technique that produces entity–relationship diagrams (ERDs), which can be employed to capture information about data model entity types, relationships and cardinality. A Crow's foot shows a one-to-many relationship. Alternatively a single line represents a one-to-one relationship. [4]
Realization - Realization shows the relationship between an Interface and the class that provides the implementation for the interface. Reference-Request - The input to the system for finding the related abstracts from different operations (Add, Del, Mod, Inq.). Request could be for only one for every operation; Response - The output of the ...
Object/Class: A tight coupling or association of data structures with the methods or functions that act on the data. This is called a class, or object (an object is created based on a class). Each object serves a separate function. It is defined by its properties, what it is and what it can do.
an arrow from an entity set to a relationship set indicates a key constraint, i.e. injectivity: each entity of the entity set can participate in at most one relationship in the relationship set; a thick line indicates both, i.e. bijectivity: each entity in the entity set is involved in exactly one relationship.
The relationship between the composite and its parts is a strong “has-a” relationship: The composite object has sole "responsibility for the existence and storage of the composed objects", the composed object can be part of at most one composite, and "If a composite object is deleted, all of its part instances that are objects are deleted ...
The network model organizes data using two fundamental concepts, called records and sets. Records contain fields (which may be organized hierarchically, as in the programming language COBOL). Sets (not to be confused with mathematical sets) define one-to-many relationships between records: one owner, many members. A record may be an owner in ...
The UML class diagram for the Membership example. UML provides an association class construct for defining reified relationship types. The association class is a single model element that is both a kind of association [6] and a kind of class. [7] The association and the entity type that reifies are both the same model element.