What's the best relational structure for implementing a FIFO product inventory?

Question

What's the best relational structure for implementing a FIFO product inventory? I need that the product entries be stored grouped by entry date and entry price, but sales from the existing stock be made in a First-In-First-Out manner, in which the product quantity representing the sale would be subtracted from the oldest entries first. The problem is that I also need a reliable way of knowing how much merchandise each entry originally had, so I could recover in case of a human error (wrong product sale and similar situations).

Answer 1

If you record all inventory transactions you can report any kind of inventory accounting (like FIFO, LIFO). As long as you record when, and for what unit price and quantity, inventory is bought, you can make any kind of historical report.