Database relation many to many

Question

alt text http://produits-lemieux.com/database.jpg

This is basicly my database structure

one product (let say soap) will have many retail selling size

• 1 liter
• 4 liters
• 20 liters

In my "produit" database I will have the soap item (id #1) In the size database i will have many size availible :

• 1liter
• 4liter
• 20liter

How not to duplicate the product 3 time with a different size... i like to be able to have check box in the product size of all the size available in the database and check if yes or no (boolean)

---

The answer a got is perfect, but how to have the option like that :

soap [x] 1 liter , [ ] 4 liter , [x] 20 liter

Answer 1

I'm not sure I understand your exact scenario, but to create a many-to-many relationship, you simply create a "relationship table", in which you store id's for the two records you want to link.

Example:

Products
********
ProductID (PK)
Price

Retailers
*********
RetailerID (PK)
Name

ProductRetailerRelationships
****************************
ProductID
RetailerID