MySQL: Count the total occupancy rate for a time period (month)
Recently I encountered a somewhat interesting MySQL/PHP task: determine occupancy for a reservation system. This entailed determining how many reservation days fall within a particular month. It was not possible to simply determine each reservation length (datediff from/to) and sum them because some reservations started before the month in question and other reservations lasted until the month was over. Therefore, one solution is to get the reservation lengths then compare the start and end of the reservation to the start