The first part of the question you answered.  I know it was not covered in that seminar, but I wanted to know where you have covered that in the past (SQL3).
The 2nd half refers to I have a table of Customers, a table of items and a transaction table.  The tranaction table contains the customerID and the ItemID. My form needs to choose a Customer, list ALL items from the items table and give a sum of each item purchased.
Example:
Customer 1
Item1 10
Item2  0
Item3  5
Item4  0
Items 2 and 4 do not have a line in the transaction table, because the customer 1 has never purchased any.  Therefore the Customer Table is not related to the item table.  My understanding it is like an outer join.

Thanks for your patience with me.

---

Reply from Richard Rost:

I would actually use FOUR tables here: Customers, Items, Orders, LineItems. This is what I set up in my Access 300-level classes (say 301 to 304).

You would have your customers and items, that's easy. Then your OrderT table would have an OrderID and the CustomerID: OrderID, CustomerID, OrderDate, IsPaid, etc. Any details about the ORDER AS A WHOLE would go in this table.

Now how do you track what items are on that order? You would have the LineItemT which would have it's own ID, the OrderID, ItemID, Quantity, etc. Any details about THAT ITEM for the transaction.

The TRANSACTION is actually the ORDER, but if that order has multiple items, then you need another table to track those items.