Title
Join Entity Attributes Solving Many to Many
Post
When resolving a many to many relationship does the join table have to have any other attributes/fields other then the 2 foreign keys to work?
If No would adding a 3rd field help it to be more effective?
Additional thanks for all the other help on my other posts!
The minimum requirements are that you have the two foreign keys. But additional fields in the join table are often useful. For one thing, a field in the join table records data to a specific pairing of records from the other two tables that simply could not be stored in either of the other two.
Example:
Invoices----<InvoiceData>-----Products
Fields in InvoiceData would record the quantities and current unit prices both items you could not effectively store in a record from invoices nor from products.