Entity Relationship Diagrams - 747 Words

An entity relationship diagram is the basic design model for any database. It is the major deliverable for a conceptual database design. It is the logical organization of any data in the database and is usually made up of three components namely; entities, attributes and relationships. Entities are the major categories of data in the database and are usually represented by rectangles. Attributes are the characteristics of the entities and are usually written in the rectangle. Relationships are the connections between entities and are usually represented using lines joining the rectangles. Entities that share major characteristics are known as entity types, and are also referred to as classes. An entity instance is the individual occurrence of one entity type. It is important to define entity types as it makes it easier to determine the requirements of the database and how it will be structured. In defining an attribute, the analyst must state the importance of the attribute, the value of the attribute and whether the value of this attribute can change. When drawing an entity relationship diagram, the analyst must be aware of the following types of attributes; multi-valued attributes, required attributes, optional attributes, composite attributes and derived attributes. When showing relationships, an analyst must be aware of three types of relationships; unary (between instances of one entity type), binary (between instances of two entity types), and ternary (betweenShow MoreRelatedEntity Relationship Diagram1225 Words   |  5 PagesEntity Relationship Diagram The bellow diagram is what is refered to as an Entity Relationship Diagram. Its purpose is to show the relationship between different data in the hotel management program , and the actions that are performed on it. And how data from different objects relate to each other. Legend The Data Entities represent data that will need to be stored on the system, in general terms. The Relationships represent actions that will occur to the Data Entities, or Weak Entities. Read MoreEntity-Relationship Diagrams and the Relational Model2499 Words   |  10 PagesReview Entity-Relationship Diagrams and the Relational Model CS 186, Fall 2007, Lecture 2 R G, Chaps. 23 A relationship, I think, is like a shark, you know? It has to constantly move forward or it dies. And I think what we got on our hands is a dead shark. Woody Allen (from Annie Hall, 1979) †¢ Why use a DBMS? OS provides RAM and disk Review †¢ Why use a DBMS? OS provides RAM and disk – Concurrency – Recovery – Abstraction, Data Independence – Query Languages – Efficiency (for most tasks)Read MoreEntity-relationship Model and E-r Diagram2109 Words   |  9 Pagesmodel 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. If K is a superkey, then so is any superset of K. A superkey forRead MoreData Modeling Using Entity Relationship Diagrams : A Step Wise Method1798 Words   |  8 Pages Best Practice: ERDs â€Å"Data Modeling Using Entity Relationship Diagrams: A Step-Wise Method† IST 659 - Syracuse University September 30, 2014 Jared S. Mandel â€Æ' Introduction Databases are the center of many technology and non-technology focused businesses. They are used in retail, healthcare, education and government. Databases are essentially in entering, storing, managing and referencing data, and can be simple in nature, or extremely complex. In order for a database to be implementedRead MoreEntity Relationship Diagram of a Video Rental Store601 Words   |  2 PagesVideo Rental Store Entity Relationship Diagram For this video rental store, the movie database contains three kinds of records namely customers, tapes, and rentals. Whenever a customer visits the video store, the database is looked at to determine whether the store attendants already know the new customer; and if not, a new record is added to update the new customer’s details (Beynon-Davies, 2004). In the database, important information about the customer that is stored includes the customers nameRead MoreApplying Normalized Tables And The Model Of The Entity Relationship Diagram Can Then Improve The Conceptual Model1206 Words   |  5 Pagesattributes within the entity table to achieve its goal. Since the Entity Relationship Diagram will also contain the appropriations amongst the attributes, as a common base to identify the entity type structure, than it is possible to then apply the normalization principles, all during the conceptual data modeling phase. Enacting Normalization during the Entity Relationship Diagram can then improve the conceptual model, and therefore speed its utilization. The Entity Relationship Diagram has acquired lotsRead MoreEntity-relationship Model and Mountain View Community1374 Words   |  6 PagesHospital want to use entity-relationship modeling to understand its data requirements? What other ways might the hospital want to model its information requirements? This hospital wants to use E-R modeling to understand data requirements. E-R modeling is very easy to understand and shows all the business rules. †¢ Entity-relationship modeling is logical representation of the data for an organization or for a business area. The E-R model is expressed in terms of entities in the business environmentRead MoreHuffman Trucking Entity-Relationship Model1667 Words   |  7 PagesThe Entity-Relationship Model ------------------------------------------------- Top of Form Bottom of Form Database Design Goal of design is to generate a formal specification of the database schema Methodology: 1. Use E-R model to get a high-level graphical view of essential components of enterprise and how they are related 2. Then convert E-R diagram to SQL DDL, or whatever database model you are using E-R Model is not SQL based. It s not limited to any particular DBMS. It is aRead MoreBec Case Study Essay1624 Words   |  7 PagesSolutions 1. Review the data flow diagrams you developed for questions in the BEC case at the end of Chapter 5 (or diagrams given to you by your instructor.) Study the data flows and data stores on these diagrams and decide if you agree with the team’s conclusion that there are only the six entity types listed in this case and in BEC Figure 6-1. If you disagree, define additional entity types, explain why they are necessary, and modify BEC Figure 6-1. The six entity types in BEC Figure 1 are theRead MoreEvolution of Data Models1122 Words   |  5 Pagesrepresenting information using parent/child relationships: each parent can have many children, but each child has only parent. All attributes of a specific record are listed under an entity type. Example of a hierarchical model In a database an entity type is the equivalent of a table. Each individual record is represented as a row, and each attribute as a column. Entity types are related to each other using 1:N mappings, also known as one-to-many relationship. This model is recognized as the first

Finding The Peripheries Sovereignty And Colonialism

In â€Å"Finding the Peripheries: Sovereignty and Colonialism in Nineteenth-Century International Law,† Antony Anghie discusses the concept of sovereignty and membership. He uses the term â€Å"family nations† to illustrate the relations of states. Anghie seeks to find the answer to how â€Å"new† Europe deal with the task of â€Å"how order is created among sovereign state.† To which he asserts that â€Å"special doctrine† of shared norms and values have been devised for purpose of determining states’ sovereignty. Hence, states have resorted to the development of an international law to help them govern and set out the criteria that are required in order to be acknowledged as a sovereign state. Anghie subsequently put forth that this â€Å"international law applied only to the sovereign states that composed the civilized â€Å"Family Nations.† This definition excluded third world countries who were deemed as being â€Å"non-civi lized states† such as â€Å"non-European states.† This definition is problematic as it a very biased perception. The term sovereign state is arguably a social construct made by European as it is mainly of a Western European origin. Anghie acknowledges that states could be formally considered â€Å"sovereign† only if â€Å"they satisfied the criteria [for] membership in the civilized international society, they lacked the comprehensive range of power enjoyed by the European sovereigns.† This ultimately illustrates how the development of international law has dominated by European as western normsShow MoreRelatedColonial Rule Of Independence And Independence10047 Words   |  41 Pagesimportant role in governing a state and adjudicating disputes, the decision to retain an extraterritorial appellate institution such as the JCPC seems counterintuitive and an affront to state sovereignty. Elden (2006) states three fundamental canons anchoring this assertion- â€Å"the notion of equal sovereignty of states, internal competence for domestic jurisdiction and territorial integrity† (p. 11). The new national governing coalition takes over the state’s institutions and bears ultimate responsibilityRead MoreCan the Subaltern Speak9113 Words   |  37 Pagesof the most radical criticism coming out of the West today is the result of an interested desire to conserve the subject of the West, or the West as SUbject. The theory of pluralized subject-effects gives an illusion of undermining SUbjective sovereignty while often providing a cover for this subject of knowledge. Although the history of Europe as Subject is narrativized by the law, political economy, and ideology of the West, this concealed Subject pretends it has no geo-political determina271 Read MoreCase Studies in IMFs Investment on the African Continent10534 Words   |  42 Pagesand the Fund has been debating and implementing piecemeal amendments since Streamlining became a topic of discussion. Major themes arise, given the number of 2001 responses. Bird among many others argues conditionality infringes on national sovereignty (2) and that while the effects of conditionality through monetary policy remain undemonstrated positive or negative; relative currency devaluation conditions generally have had stabilizing effects, but cause inflation; which is usually offset byRead MoreOne Significant Change That Has Occurred in the World Between 1900 and 2005. Explain the Impact This Change Has Made on Our Lives and Why It Is an Important Change.163893 Words   |  656 Pagesthe decades that followed the Great War, the victorious European powers appeared to have restored, even expanded, their global political and economic preeminence only to see it eclipsed by the emergence of the Soviet and U.S. superpowers on their periphery and a second round of even more devastating global conflict. The bifurcated international system that resulted from the cold war standoff extended the retreat of globalization, but nurtured the liberation of most of humanity from colonial ruleRead MoreNational Security Outline Essay40741 Words   |  163 Pagesunder customary international law; ICJ Nicaragua opinion: state that is the victim of such an armed attack has to request the collective defense. Serious covert attack against government and political institutions, aimed at the core of national sovereignty, is the functional equivalent of an open invasion to which states have a right to defend themselves; If this were not the norm, such covert/indirect aggression would be encouraged and world order would be negatively affected. Charter makes inRead MoreOrganisational Theory230255 Words   |  922 Pagesimplications of questions 1 and 2 for the effective and efficient management of organizations? . The relationship between organization theory and management practice 21 4. How can organization theorists design their research and communicate their findings so that it is perceived as relevant to the problems faced by practising managers and is accessible to them? For example, the observation of management practices in what have been categorized as exemplary or ‘excellent’ organizations has been presented

The left hemisphere and right ... free essay sample

The left hemisphere and right hemisphere of my brain are constantly in a tussle for dominance. Whenever reason and logic successfully persuade me to focus on exploring the profundity of, say, Gauss theorem or Luria–Delbrà ¼ck experiment, sensibility and creativity would soon manifest their power to regain control, requesting me to act on intuition, for example, improvising a calligraphy work, or producing a drama of William Shakespeare. Worse still, there seems no ending to the battle, as recently it has been respectively strengthened by the urge to learn MATLAB scripting and curiosity for a cappella singing.Dedicated to cultivating Scholars, Creators and Makers and with great strength in neuroscience study, CMU initially attracted me as the forefront to study the biological base for my brain dissonance, and find out pragmatic ways to terminate it. Specifically, I plan to obtain a solid base for upper-level life science study: from fundamental understanding of areas such as gene expression and regulation, and molecular mechanism of intercellular transmission, to hands-on programming, statistical and lab skills to help test, for example, how specific genetic markers play in predisposition to certain diseases. We will write a custom essay sample on The left hemisphere and right or any similar topic specifically for you Do Not WasteYour Time HIRE WRITER Only 13.90 / page Therefore, with well-structured courses from Genetics, Experimental Biology, Organic Chemistry to Intermediate Programming, the curriculum set for Biological Sciences majors makes a good fit for my academic craving. Building upon such a foundation, I hope to actively participate in the abundant research opportunities, from volunteer ones to credit-earning ones, work closely with top-notch professors on world-changing researches, and most importantly, develop an intimate understanding of how biological knowledge is actually discovered and applied. For example, as my brain dissonance is constantly changing in response to my everyday experiences, Im interested in participating in ongoing researches at the Barth Lab to discover the underpinning mechanisms. Plus supportive experimental facilities and intense academic atmosphere, Ill delve into intricacy involved in the causes of incurable diseases and effective drug and biotechnology development, facilitate the progress of medical resear ch and transform healthcare for the better. While investigating CMU for more possibilities to satisfy my curiosity for brain dissonance, Ive also caught a glimpse of its encouragement for interdisciplinary study, and translation of integrated knowledge into social-minded action, as can be evidenced by the Global Water Brigades program. This further inspired me to rethink about the duality, and even multi-facets of my brain frenzy. Just as Steve Jobs once incorporated his calligraphy study into the flagship development of multiple typefaces and proportionally spaced fonts in Mac, I believe somewhere I could convert the multiple factors involved in my brain frenzy into advantages to achieve greatness in a similar way. At CMU, I could be fully attired at The Jubilee Conference to communicate with like-minded collegiate students how my biological research could potentially change the way diseases will be diagnosed and treated, while wildly yelling out for the victory of the women volleyball team in a spring tournament as an enthus iastic fan; I could temporarily liberate schoolmates from endless coding by teaching them how to achieve equanimity and endurance to excel with calligraphy writing through TEDxCMU, while lightheartedly enjoying a concert offered at AB Coffeehouse†¦ With the education at CMU, I aspire to step into more unknown arenas to satisfy my brain frenzy, but only add to the establishment of an unconventional wisdom, whichll continually help me stay true to myself while enacting transforming changes for advancement in biological and medical sciences!