RANDOM() not working in Rails 4.0.2

Question

I was using the following method in my Rails 4 app to get random records in a model:

Model.order('RANDOM()').limit(5)

This broke after upgrading to Rails 4.0.2. It's always getting the most recent records. Any ideas why?

SELECT "model".* FROM "model" ORDER BY created_at DESC, RANDOM() LIMIT 5 — 6thSigma, Feb 03 '14 at 18:34
Do you have some default ordering scope on `Model` that you are not aware of now? — steakchaser, Feb 03 '14 at 18:35

score 2 · Accepted Answer · answered Feb 03 '14 at 18:39

2

You either need to remove the default scope from your model or call it like this:

Model.unscoped.order('RANDOM()').limit(5)

answered Feb 03 '14 at 18:39

Philip Hallstrom

score 0 · Answer 2 · answered Feb 03 '14 at 18:38

0

Simply use Model.all.sample(5)

answered Feb 03 '14 at 18:38

Ishank Gupta

1

This may work okay for very small data sets, but the above will be very inefficient if Modal.all returns any significant number of rows as they will all be returned, objects instantiated, and only then will Array#sample randomly pick 5 of them. – Philip Hallstrom Feb 03 '14 at 18:41
2

[For more information of what Philip is referring to](http://stackoverflow.com/a/12038506/877472) – Paul Richter Feb 03 '14 at 18:42
Yup...got what you are saying. Thanks. – Ishank Gupta Feb 03 '14 at 18:46

2 Answers2