d.A data analyst has been asked to model the data necessary to record site inspections of locations at which events are held.

Consider the following description of location visits which extend the Eventbase scenario. The details in this description have been agreed by the company as an accurate summary of the visits they undertake.

• The suitability of each Location used to host events is checked by a site visit. Eventbase want to record details (such as date, time, visiting employee, findings) of each visit. Each visit is made to a single location.

  When a new location is identified (a location not previously used for an event) its data is entered into the Eventbase database and it is recorded as inactive and an initial visit is recorded for that location. The initial visit is an in-depth scrutiny of the location to ensure health and safety arrangements are appropriate and that the site accessibility and facilities available meet the Eventbase minimum standards. If the location doesnt meet the standards then a list of required changes is given to the owners and a return visit is arranged; the location status remains inactive. If the required changes arent made then the location is not accepted by Eventbase and its status is changed to do not use. When the location is approved its status is changed to active.

  Each active location in the Eventbase database is also subject to an annual site visit to ensure it is being properly maintained and the facilities remain unchanged. If the location is no longer acceptable the location is recorded as inactive until a later visit approves the location.

  A random visit can be made at any active location at any time; this assures the site condition is satisfactory between the regular, annual visits.

The data analyst has considered the information in the above description. He wants to model the relationship between the locations in the database, and the visits used to inspect the facilities, etc. However, hes not sure of the degree and optionality he should show for the relationship.

Hes shown three alternatives in Figure 3, (calling them IsMadeTo1, IsMadeTo2, IsMadeTo3).

In Figure 3, details of all visits, initial, annual and random, are in a Visit entity type. Details of all locations are held in a Location entity type.

Figure 3 An entity-relationship diagram

Long description

Write down sentence pairs, showing the degree and optionality, for each relationship type (IsMadeTo1, IsMadeTo2 and IsMadeTo3) shown on Figure 3 (make sure you label each pair of sentences clearly with the name of the relationship type for those sentences.

Identify, from the three shown in Figure 3, the relationship type that has the degree and optionality that matches with the information given in the short EventBase scenario above it.

Then justify your answer by identifying the mismatches between each of the other two relationship types shown in Figure 3 and the information in the short EventBase scenario above.

Entity Type> Visit Entity Type> Location Is Made To 1 1..1 has is made to 0.m 1..m has Is Made To2 is made to 1..1 0..m has Is Made To3 is made to 0..1 Entity Type> Visit Entity Type> Location Is Made To 1 1..1 has is made to 0.m 1..m has Is Made To2 is made to 1..1 0..m has Is Made To3 is made to 0..1