This week's book giveaway is in the Servlets forum.
We're giving away four copies of Murach's Java Servlets and JSP and have Joel Murach on-line!
See this thread for details.
The moose likes Architect Certification (SCEA/OCMJEA) and the fly likes Data model against a class diagram Big Moose Saloon
  Search | Java FAQ | Recent Topics | Flagged Topics | Hot Topics | Zero Replies
Register / Login


Win a copy of Murach's Java Servlets and JSP this week in the Servlets forum!
JavaRanch » Java Forums » Certification » Architect Certification (SCEA/OCMJEA)
Bookmark "Data model against a class diagram" Watch "Data model against a class diagram" New topic
Author

Data model against a class diagram

Anjan Pathak
Greenhorn

Joined: Apr 16, 2004
Posts: 1
This is something I have always encountered while creating a data model to fit a class diagram.
A simple scenario to consider is : A customer, a credit card and a Payment class. For simplicty a customer has got one credit card, can have many orders and pays them with his single credit card.
A credit card can belong to a payment object and also to a customer. In terms of storing them in database, both has to be stored in different tables. Why ? Cause a payment object cannot just point to the customers credit card. A payment object should point to a credit card that was used while paying. However the credit card details associated with the customer can change over time. I have got two options :
1. Store them in the same table but in different rows representing different objects. In this case we can assoicate the same class to customer and payment.
2. Create two different classes i) Customer Credit Card ii) Payment Credit Card and persist them in different tables.
Which option is better and why?
[ April 16, 2004: Message edited by: Anjan Pathak ]
 
 
subject: Data model against a class diagram
 
Similar Threads
Cade's Class Example use of Association
Class diagram and business objects
Different payment types
Cade's Class Diagram question... Please Help
Some questions about Cade and Roberts' case study