0

I am learning the data model and came accross this situation where a relationship SELLS between manufacturer and Products entities. I don't know how to represent the bolded statements in the question below:

" Manufacturers are identified by their name; they have an address and a phone number. Each manufacturer usually sells several products, with distinct names. However, two products from two manufacturers might have the same name. "

Is it possible to make it visible in the diagram? If yes, how ?

Brian Tompsett - 汤莱恩
  • 5,753
  • 72
  • 57
  • 129
Chrisantics
  • 165
  • 2
  • 16
  • means you need a table between Products and Manufacturer. and on that table you need to have the product name. When a manufacturer over time deviates from the common name, you can still behind the scenes call it the same thing but when dealing with the Manufacturer, use the product name from the associative table. On the surface it means create a unique index on Product Name on the products table, but allow that value to be overwritten at the Manufacturer_products association. (just my 2 cents) – xQbert Dec 10 '14 at 21:32
  • Thank you for your reply, appreciate it! I have stumbled upon somewhere, it says that Product could be the weak entity and needs suppporting of attributes from Manufacturer to uniquely identifies each records. I think that it could make sense also. :) @xQbert – Chrisantics Dec 10 '14 at 21:50
  • in OO terms think of product as a base object which gets extended and or overloaded by attributes on the Manufacturer_Products table. which further refine product specifics for a given manufacturer. – xQbert Dec 10 '14 at 21:53

0 Answers0