Just thought about what would be happening by changing the OrderUserID field to accept null data, going off the tutorial on this site about making a back end database, it is using the OrderUserID field as a unique identifier to connect each order with its individual items associated with it. So if i make it accept null data which I assume the majority of the time it will be sending, there is no link between my order summary and its contents, I would need a method of ensuring that each new order summary has a unique ID field, and that each order detail associated with it, also has this value to link them.