How do I handle a definition that has no neutral term? [closed]

Question

The financial application I am building contains data which is a number that corresponds with two terms. It works like this:

• number > 0 = overspend
• number < 0 = underspend

Unfortunately the overspend/underspend terms do not have a neutral term, like nospend or whateverspend. Now I'm unsure about how to save this data in for example a database column. What name do I give to this database column? Or how do I handle it in my back-end? double <...spend> = // a number?

So, like the question says: How do I handle a definition in my application that does not have a neutral term, but either a positive one, or a negative one?

Answer 1

You wouldn't save the overspend/underspend flag. You would save "number". Then you can always check if it is positive, negative or 0 in query/view or in business logic.

If you save both "number" and the overspend/underspend flag then you have redundant data in the database with is bad for several reasons, most importantly you open the possibility that they could get out of sync (eg. "number" is updated but you forget to update the flag).

If you have say "budget" and "expenditure" as two columns, then you don't need to also save the difference between these two, which seem to be what "number" is.

Answer 2

Name the variable as if it's always positive. Having a negative value already implies the opposite situation. So, in your case, use overspend.

For example; a negative value in a variable called profit implies loss rather than actual profit. A negative value in time_until_X implies X already happened.

Answer 3

You could name your column "Spend" which contains "under" when number < 0, "over" when number > 0, otherwise NULL.