Database Answers Allotments in Covent Garden, London (Click for Web Site)

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Garden Allotments   
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The Area being Modelled is :-
Garden Allotments

Somebody writes 

Subject: Please I would need the Entity Diagram for this Two questions. I have written down some of the attributes,
Question: This is to draw an Entity Relationship Modelling Diagram that will show inside dot for the "Must Need" end and outside dot on the "not must" end. 
You also need to put 1s and Ms relationship where needed. 

Question (2) This is to draw an Entity Relationship Modelling Diagram that will show inside dot for the "Must Need" end and outside dot on the "not must" end. You also need to put 1s and Ms relationship where needed. London Allotments London City Council's allotment department is responsible for the city's allotments. Allotments are small areas of land that can be rented by council residents to grow vegetables and fruits. These allotments are rented by individuals. A site may have a paid manager who looks after the site and carries out any maintenance (such as repairing gates and fences): in this case, basic details of the manager are stored. As the site are spread throughout the city, each manager looks after exactly one site. A gardener rents a numbered allotment by paying the rented fee. Some gardeners rent several allotments but an allotment can only be rented by one named person. The allotments are in great demand and are never left vacant. Gardener's details are recorded as soon as they are accepted for the waiting list, together with the date they were added to the list. Suggest suitable attributes for each table(assume that these will be discussed in details with the users when you next meet with them) Extension to the scenario: This scenario encourages you to draw an ERD that records only the current manager of each site, not previous managers. Similarly you were only expected to record the current gardener for each allotment. How would your diagram change if the council wanted to keep records of all the managers and gardners over several years ? Does the basic rule for allocating foreign keys work for the new diagram? We are going to need more techniques, aren't we ? My Answer: Attributes:-
  • Council(CouncilID, Address, Telephone, Location)
  • Manager(ManagerID, Fname, Lname, Address, DOB, Gender)
  • Site(SiteID, RegistrationNo, Size, Location)
  • Gardener(GardenerID, Lname, Address, DOB, Gender)
  • Allotment(AllotmentID, RentalFee, NameOnRent, AllocatedDate, ExpiryDate, RentDuration, AllocationSize, WaitingList)
  • Individual(IndividualID, Fname, Lname, Address, DOB, Gender)
    Barry has identified the 'Things of Interest' as follows :- 1. Councils 2. Individual 3. Sites 4. Observations 5. Others to be determined
    Question (1) The All Day Driving School The All Day Driving School has a number of instructors. Each instructor is assigned a car for their own use only. The school also has a spare car which is not assigned to a particular instructor. The driving school takes on pupils who are each allocated to an instructor. The pupil then books lessons with the instructor. New instructors have a short induction period before any pupils are allocated to them. Suggest suitable attributes for each table (assume that these will be discussed in detail with the user when you next meet with them). Extention to the scenario: Sometimes the pupil's allocated instructor is not available when he/she requires a lesson, and a different instructor cover that lesson. How would you amend your diagram and tables so that it is still possible to identify the allocated instructor, but also to record who was the instructor for each lesson ?. MY Answer: Attributes: Institution(InstitutionID, Name, Address, Telephone, Location) Instructor(InstructorID, Fname, Lname, Address, DOB, Gender) Car(CarID, RegistrationNo, Make, Model, Colour) Pupil(PupilID, IntructorID, LessonID) Lesson(LessonID, InstructorID, CarID, StartDate, EndDate, Cost, Details)


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