Design database structure to store weekly chart positions?

Question

Suppose to have something like:

Top 10 Products (WK 51)

1. Product1
2. Product2
3. ...
4. Product9

What can be a good database structure to store weekly charts that allow easy post-processing analysis like a graph of chart positions for a certain productID?

Answer 1

Table Chart:
    id int
    productid int
    rank int
    week datetime
    comments text

When querying, select by date range. In our workplace, we have a table we can join to with date information (weeks, minutes, intervals, seconds etc).