I have a database that manages highway traffic (it's a project for one of my classes).
I need to have information on clients, their trips in my highway system, how much they have to pay.. etc...
However i want to future proof my db. Imagine that the tax that i have to deal with is updated every year (or even randomly) how can i change the its value in the database without altering my previous records??
I know that you don't work for other people, i don't want that anyway..
It's a request and a goal that I've put to myself.
I have a table with the fields: "Date In" "Date Out" and "Tax":
"Date In" refers to the date that the new tax percentage is activated by the government, and "date Out" is the last day that the tax is in place.
"Tax" is the percentage that is applied to my transaction.
Is there a specific function I can use? or do i have to use a complex Iif function?