Ok this is probably not what your after, but it may help, this information is a little old but should give you a bit of an answer if not ah welllll I tried :)
http://tinyurl.com/zckcv
1. Entity set
2. Attributes
3. Relationship sets
An entity-relationship diagram for online banking includes the process of online banking and the relationship between each step. It is a model that maps out, describes, and defines how components are linked for online banking.
Entity Attribution Relationship
ENHANCED ENTITY RELATIONSHIP OR EXTENDED ENTITY RELATIONSHIP
entity relation model for hospital database
yes
is called specialization and generalization.
Entity-Relationship diagrams are useful for modelling data and the relationships between the data. They can be used when the constraints between data are relatively simple. They do not allow specification of interactions between the data or model how the data changes (there are no processes in Entity-Relationship). Entity-Relationship diagrams are most often used to model databases.
Entity-relationship model advantages and disadvantages AdvantagesDisadvantagesConceptual simplicityVisual representationEffective communicationIntegration with the relational database modelLimited constraint representationLimited relationship representationNo representation of data manipulationLoss of information
mandatory and optional
AdvantagesConceptual simplicityVisual representationEffective communicationIntegration with the relational database model
In software engineering, an Entity - Relationship model(ER model for short) is an abstract and conceptual representation of data. Entity-relationship modeling is a database modeling method, used to produce a type of conceptual schema or semantic data model of a system, often a relational database, and its requirements in a top-down fashion. Diagrams created by this process are called entity-relationship diagrams or ER diagrams.learn more www.ngprakasam.hpage.com
E.R. model is an abstract and conceptual representation of data.... it is a graphical representation of entities and their relationship to each other..