How should I setup the structure of my MySQL database to work for my needs?

Question

I am working on an application that awards the top person of each category for being first. The way you become first in a category is by having the most number of votes in the past 30 (or so) days. So even if you had a total of 2,000 votes but got only 2 votes within the past 30 days, someone with 10 votes but got all 10 within the past 30 days would be ranked above you. I am just trying to seek advise on the best way to create this type of system with a MySQL database and how to structure the database.

I am pretty unsure of the best way to go about this, any advice would be greatly appreciated!

Answer 1

The first desicion you have to make is, whether you want to keep a record for every vote cast: This has the potential for a huge table, but it lets you keep a lot of information, so you trade storage and performance against information. This must be answered by business logic, not implementation.

Assuming you DO want to keep every vote, keep it with a timestamp and the only thing you have to do is to join the user person table with the vote table, use a WHERE clause to select only the last N days and a COUNT() aggregate to count your votes.

If you do NOT want to keep every vote, you should have an accumulation table with person, day and votecount - an analogous query with SUM() instead of COUNT() will do what you want.