Displaying random but fair MySQL results

I am trying to display random MySQL results for featured items on my site. While I want it to be random, I also want it to be "fair".

The scenario is like this; I have 4 featured customers. Customer 1 has 100 items, Customer 2 has 75 items, Customer 3 has 50 items, and Customer 4 has 25 items. I am displaying 4 items at a time. Note that I use 4 Customers as an example but could have 1000's.

Currently, items from Customer 1 show more then the others because there are more records in the db for this customer. How can I make it so the items are displayed more "fairly" yet random? Ideally, it would only display one item per customer.

Here is the MySQL query I am currently using, it is very simply.

SELECT fields WHERE some='condition' ORDER BY RAND() LIMIT 4

 

What about something like this:


select t1.*
from tableName t1
join (select columnName, min(ID) as MinID
from tableName group by columnName) t2 on t1.columnName= t2.columnName
WHERE t1.ID= t2.MinID
ORDER BY RAND() LIMIT 4

 

I'll have to test it and let you know ... looks like it may just do what I need. Thanks for the help!

 

Seems to be better results then RAND() but slower...