Rails 5—get a random record from db?

You can try following database independent query:

User.find(User.pluck(:id).sample)
[DEBUG]  (36.5ms)  SELECT `users`.`id` FROM `users`
[DEBUG] User Load (0.5ms)  SELECT  `users`.* FROM `users` WHERE `users`.`id` = 58229 LIMIT 1

this one fires two queries but this one is performance efficient as it took only 37ms to get single random user record.

whereas the following query will take around 624.7ms

User.order("RAND()").first
[DEBUG] User Load (624.7ms)  SELECT  `users`.* FROM `users`  ORDER BY RAND() LIMIT 1

I have checked this for 105510 user records.

Using Postgresql or SQLite, using RANDOM():

User.order("RANDOM()").first

Presumably the same would work for MySQL with RAND()

User.order("RAND()").first