E-R Diagram Introduction:- In 1976 ‚Chen developed the Entity-Relationship Diagrams ‚a high-level data model that is useful in developing a conceptual design for database . An ER diagram is a diagram containing entities or “items”‚ relationships among them‚ and attributes of the entities . The E-R model is one of the best known tools for logical database design. Within the database community‚ it is considered a natural and easy-to-understand way of conceptualizing the structure of database.
Premium Entity-relationship model
1. What is an Entity Relationship Diagram? An entity relationship diagram is a graphical representation of an organisation’s data storage requirements. Entity relationship diagrams are abstractions of the real world which simplify the problem to be solved while retaining its essential features. Entity relationship diagrams are used to: identify the data that must be captured‚ stored and retrieved in order to support the business activities performed by an organisation; and identify the data required
Premium Entity-relationship model Relationship
August 3‚ 2013 Week 4 Problems and Exercises Chapter 7 5) Consider the E-R diagram in Figure 7-20. Based on this E-R diagram‚ answer the following questions: a. How many EMPLOYEES can work on a project? There is no set limit of employees to work on one given project. b. What is the degree of the Used on relationship? There are 2 degrees for the Used on relationship. c. Do any associative entities appear in this diagram? If so‚ name them. Yes there is task which is an associative
Premium Entity-relationship model
Exercises 9 address driver-id person name owns license model year car report-number location date driver participated accident damage-amount Figure 2.1 E-R diagram for a Car-insurance company. Exercises 2.1 Explain the distinctions among the terms primary key‚ candidate key‚ and superkey. Answer: A superkey is a set of one or more attributes that‚ taken collectively‚ allows us to identify uniquely an entity in the entity set. A superkey may contain extraneous attributes
Premium Entity-relationship model
Chapter 4 The Enhanced E-R Model and Business Rules Chapter Objectives The purpose of this chapter is to present some important extensions to the E-R model (described in Chapter 3) that are useful in capturing additional business meaning. In particular we describe two types of extensions to the E-R model. The enhanced entity-relationship (EER) model includes constructs for supertype/subtype relationships. The inclusion of new notation for business rules allows the designer to capture
Premium Entity-relationship model Object-oriented programming Object
implicitly cedes the moral imagination to the sexual revolutionaries because the words “fornication” and “premarital sex” aren’t interchangeable. Fornication isn’t merely “premarital.” Premarital is the language of timing‚ and with it we infer that this is simply the marital act misfired at the wrong time. But fornication is‚ both spiritually and typologically‚ a different sort of act from the marital act. That’s why the consequences are so dire. Fornication pictures a different reality than the
Premium Marriage Sexual intercourse Christianity
e-Business Model‚ Venn Diagram Technology Application and e-Marketing – MKT552 February 18‚ 2013 Howard Kersey Introduction The e-Business sector is seeing tremendous growth at a time when technology is the lifeline for many people. Online business models are used to convert new technology to economic value. For some start-up companies‚ familiar business models cannot be applied‚ so a new model must be devised to fit the vision for the new entity. Not only is the business model important
Premium Strategic management Management Marketing
Methodology This tells how‚ when and where you will collect information. Why have you selected a particular method of data collection (advantages)? How many questionnaires or interviews were administered? How many questions were on the questionnaires or in the interview schedule and when were they collected? Formulating Questionnaires: Look at the aims and form questions based on these aims and all the questions must relate to the topic chosen. Summary of Findings This section should provide
Premium Critical thinking Jamaica Ethiopia
Associate Level Material Appendix E Physical Security Policy Student Name: Aaron Neary University of Phoenix IT/244 Intro to IT Security Instructor’s Name: KEVIN SWINSON Date: August 9‚ 2013 Physical Security Policy Due in Week Five: Outline the Physical Security Policy. Merkow and Breithaupt (2006) state‚ “an often overlooked connection between physical systems (computer hardware) and logical systems (the software that runs on it) is that‚ in order to
Premium Physical security Security
Analyze J&R Electronics using competitive forces and value chain models. What is its business model and business strategy? How does it provide value? • J&R’s use of Loyalty’s Labs’ Blue Martini software is a classic example of Michael Porter’s approach to using the internet as an “enabling strategy” and as a “complement to and not a cannibal of traditional ways of competing”. Unique visitors are customers that go directly to the J&R site versus arriving through another site. Once there‚ J&R offers
Premium Strategic management Sales Marketing