
Originally Posted by
orange
Let's call it tblSuppliesModel(id, SupplierId,ModelId,SupplyDate,AgreedUnitPrice, Quantity)
id is unique identifier autonumber
supplierId is from tblSupplier
modelId is from tblModel
SupplyDate is the date of this specific transaction
Quantity is the number of this Model Supplied in this transaction
AgreedUnitPrice is the agreed upon/negotiated price for this transaction.
................................Not necessarily the price recorded last month, last week etc.
SupplierId,ModelId,SupplyDate are components of a composite unique key to prevent duplicates.
So a this transaction (PurchaseOrder or whatever) involves this Supplier, this Model on this Date. The Quantity of Modles and the UnitCost effective for this Order is all contained in the junction table.