急急求救...关于entity-relationship diagram的CASE...急!

tmd1

The following information relates to a Catering Company.

“We hire out marquees (tents), tables, chairs, crockery, linen and other equipment for various events such as parties and weddings.  The information we hold on our customers includes customer number, name and address and the events held by our customers (identification, date and location).

We normally stock several duplicates of the same piece of equipment (e.g. we hold 2000 plain white soup bowls and 20 large marquees). All items have a unique stock number and details are kept of quantities of all items stocked.  Large items (e.g. marquees) also have unique identity numbers and, when hired out, we records which item(s) the customer has taken for a particular event. For smaller items (such as plates) there are no individual identity numbers.  Again we record the quantity of these items hired for particular events using the stock number as identification.

Large  items are sometimes sent to a repair company (assume one only) and we record, for each repair, the details of the damage, the date when the item was sent, the details of the repair made and the cost.

Each type of equipment has one preferred supplier where we go to get replacements. Details are held of the supplier number, name, address and contact person”





1.        Describe all relevant entities and their associated attributes.
2.        Draw an entity-relationship diagram, clearly showing all relationships (i.e. 1-1, 1-M, N-M) between the entities as well as the Mandatory and Optional participating conditions.  (Remember all M-N relationships should be decomposed into two 1_M relationships)
3.        Map the entities and relationship from 2 above into a set of relational tables.
4.        Define the primary key for each of the tables from 3 above.
5.        By drawing determinacy diagrams for each table from 3 above, show that each table is fully normalized.
6.        Define the foreign keys for each table.  
      The solutions to all of the above tasks should be submitted in the form of a report.



根据前面的阅读材料回答后面6个问题...最好可以用VISIO..
朋友急求..才放到这里...希望会的朋友帮忙..在此感谢了...