We have been having trouble with customers duplicating their orders. Finding the cause is a subject for a different question. We are using a module we bought that overrides default cart behavior a bit.
I noticed that the duplicated orders have the same quote id. I was thinking that in the custom
saveOrderAction() method, I could detect if an order with that quote id already exists. I would assume there is no reason someone would buy the same cart twice. I don't want to cause false positives though.
Is there a valid reason that two orders in the
sales_flat_order table would have the same value for the column