Assuming a StockItems Table and a Transactions Table. If I want the Transactions Table to have a Foreign Key into the StockItems, and the StockItems to have a foreign keys into Transactions, there's no way I will be able to add a record in both tables (some Transactions will add StockItems) during the same transaction if I make both Foreign Keys non nullable.
a) Is there?
b) Is it ok the set foreign keys nullable?
c) Is it not best practice to cross reference like this?
d) is there anything else wrong in my reasoning?
If things have the tendency to go your way, do not worry. It won't last. Jules Renard.