Back to the Conceptual Data Model.
PURPOSE OF THESE FACTS :-
These FACTS define the functional requirements which the Database must meet.
They form the basis for agreement between the User and the Database Designer and are
written in a form of structured English which is clear and unambiguous.
The Draft FACTS have been defined and are detailed here ...
A. The Area being Modelled is :- Car Service Center
User Requirements :-
John had enough of being an academic continuously being on the red and the
manager of his bank on his back at all times.
Therefore, he has decided that he will quit from next year and using some money he inherited and a
loan from the bank to open a Car Service Center.
The way he sees it is that people own car(s) which need service.
Some people (customers) will bring their car(s) to his company for service probably annually.
He will hire some mechanics that will take care of the service by identifying the part(s) of the
car need replacing.
1. Draw an E-R diagram to show entities, attributes, primary keys, cardinalities etc.
2. Convert the entity sets and the relationship sets from the E-R diagram into tables.
Underline the key for each table and justify the selection of keys
B. The Things of Interest, ('THINGS'), include :-
B.2 Car Makes and Models
C. These THINGS_OF_INTEREST are Related as follows :-
C.1 Each Customer buys one or many Products.
C.2 Each Customer can have none, zero or many Maintenance Contracts.
C.3 Each Customer takes zero, one or many Customer Actions at intervals.
C.4 Each Contract covers one and only one Product.
C.5 Each Product can be supplied by one or many Suppliers.
D. What else do we know about the THINGS_OF_INTEREST :-
D.1 To be determined.
E. Sample Data includes :-
E.1 To be determined
F. Typical Enquiries include :-
F.1 To be determined.
11th. March 2002