How to add “weights” to a MySQL table and select random values according to these?

Question

I want to create a table, with each row containing some sort of weight. Then I want to select random values with the probability equal to (weight of that row)/(weight of all

Answer 1

I'm not an expert in probability theory, but assuming you have a column called WEIGHT, how about

select FIELD_1, ... FIELD_N, (rand() * WEIGHT) as SCORE
  from YOURTABLE
 order by SCORE
 limit 0, 10

This would give you 10 records, but you can change the limit clause, of course.