Good afternoon.  I have built several applications, with latest being a labor tracker (not a time clock).  Also an inventory tracker.  Same issue with both is if price/salary is changed on the product/person table, then price also changes on all of the past entered data.  
After almost giving up, i thought a way to get around this is that i created an update query to a new table, then a delete query to erase the new information.  Both query's are updated when data is entered.  I know there must be a better way to accomplish. Thank you,
Edgar