Postgresql Rails: Select random record within a certain range?

Question

I have in my controller the following code to select a random photo:

@photo1 = @contest.photos.limit(1).order("RANDOM()")

I wish to select another random photo as @photo2 but its score attribute must be +/- 400 of @photo1's score. How would I do this?

Optional: I rather @photo2 be within +/- 200 of @photo1's score, and if there isn't any, then search +/- 400

Answer 1

You can use where with a range to generate a BETWEEN statement.

Photo.where(score: ((@photo1.score-200)..(@photo1.score+200)))
     .order("RANDOM()").take