Bài giảng Romney_ais13 - Chapter 17: Database Design Using the REA Data Model

Database Design Using the REA Data ModelChapter 1717-1Learning ObjectivesDiscuss the steps for designing and implementing a database system.Use the REA data model to design an AIS database.Draw an REA diagram of an AIS database.Read an REA diagram and explain what it reveals about the business activities and policies of the organization being modeled.17-2Database Design Process17-3Data ModelingProcess of defining a database so that it faithfully represents all aspects of the organization, including its interactions with the external environment.Entity-relationship (E-R) diagramsREA data model17-4REA Modeling ResourcesThings that have economic value to the organization (e.g., inventory, cash)EventsVarious business activities that management wants to collect information onAgentsPeople and organizations that participate in events (both internal (e.g., employees) and external (e.g., customers/vendors) to the organization)17-5REA Basic Template17-6Creating an REA ModelIdentify relevant eventsGive-get exchange (economic duality)Identify resources and agentsResource reduced in give eventResource acquired in get eventDetermine cardinalities of relationshipsNature of the relationship between the two entities17-7Cardinality Notation MethodsGraphical symbolsGraphical symbols represent minimum–maximum cardinalities(Min, Max) notationPairs representing the minimum–maximum cardinalitiesUML notationPairs representing the minimum–maximum cardinalitiesMaximums only (Microsoft Access)17-8Key TermsData modelingEntity-relationship (E-R) diagramREA data modelResourcesEventsAgentsCardinalitiesMinimum cardinalityMaximum cardinalityOne-to-One (1:1) relationshipOne-to-Many (1:N) relationshipMany-Many (M:N) relationship17-9