返回给定值的10％以内的MySQL行

Question

I have a table in a MySQL database that looks like this:

   username   rating
1  xxxxxxxx     -1
2  xxxxxxxx      5
3  xxxxxxxx      14
4  xxxxxxxx      23
5  xxxxxxxx      12

Now if I had a given value, say 13, how would I go about returning all the rows where the rating is within 10% either way of 13?

Answer 1

SELECT *
FROM `tblName`
WHERE `rating` BETWEEN 13 * 0.9 AND 13 * 1.1

That will work perfectly.

Answer 2

SELECT * FROM mytable WHERE rating BETWEEN ? * 0.90 AND ? * 1.10

Answer 3

low = min(0, 13 * .9)
high = max(25, 13 * 1.10)

assuming maximum rating is 25. From there it's just basic low < rating < high query logic.