Where Have I Gone Wrong!!

[scouser]

Thanks

Neil, thanks for all your efforts.

I can see where you are coming from. I did think to myself that I can purchase a PC from a number of suppliers, not just HP so supplier is probably the wrong naming convention (should have stuck with manufacturer!!) as this is what I meant!!

In an earlier version I had tblComputers / tblComputerManufacturers / tblComputerModels. I also had tblHardware. This resulted in duplication as tblComputerManufacturers held HP / Dell etc...... as did tblHardware (as they also make printers etc...). I also had tblSoftware that held values Microsoft & Office 2003 etc.... Have now refined this so tblSuppliers holds HP & Microsoft etc...and tblSupplierProducts holds model numbers / software versions.

Boy do I ramble on!!

Phil.

 

[neileg]

You said earlier:

A Supplier (i.e. company that manufacturers the product, Microsoft / HP / Dell) can supply 1 or many products. A product (Windows XP / Precison 650 / nx6400) is supplied by 1 supplier.

And I said

I haven't checked this out, but I believe it's because you have the SupplierID in tblComputers. It shouldn't be there because it's an attribute of the product.

Alternatively, if the same product can be sourced from several suppliers, then it is an attribute of the computer, but not an attribute of the product.

That's why I said supplier was an attribute of the product.

Now getting away from the word 'supplier'. The manufacturer is an attribute of the product. The vendor is an attribute of the computer. You decide which one you want to store! If you want to store them both, that's fine, just be clear and preferably don't use the same field name for two different types of data.

 

[scouser]

The choice is mine then........

Neil I am always confusing myself!!

The choice is mine then........just need to make a decison then stick with it!!
Phil.