First, thank you for an introduction to a command I've never heard of. I'll need to read up on it to see if it has an application for us.

But the thing that throws me off, and I know this is basically off topic, is why would you have the quantity of an item in a separate table from the item itself? It will always be a 1 to 1 relation, so I would think it would be more efficient to have quantity as another field in the item table. Yes, I realize you always want to use a greatly simplified table setup to demonstrate a command, but I was curious what your real world data structure is like. Do you actually have a table just to keep track of quantities, or are there additional fields that would warrant the extra table and just aren't relevant to the demonstration? Is there significant performance that can be gained by this structure?

Thanks,

Ken