what will happen if two order placed simultaneously

[charlestcr]

....what will happen if two order placed simultaneously....if stock is less ..what will happen...i want out of stock products cannot be ordered... 

[Dh42]

One will be placed before the order and the other order will be rejected as not having enough product in stock. The orders table is locked when an order is being written to the database, so when the other order will be placed in a wait state for a few milliseconds while this is happening, then when the first order is done, the second will start to process and check the stock. There will be a stock error so it will kick them out.