How do I select all records with more than n child records

Question

For the situation where Employee has_many Clients, I am trying to write an ActiveRecord query that will return all of the Employees that have n or more clients. It's simple enough to write a join query to find all of the Employees with at least 1 client but extending my query to this more general case has left me stumped.

Edit - I should add that I'm trying to do this entirely at the database level. I want to avoid iterating over the collection in Ruby.

Answer 1

感谢mu和vijikumar,这就是我想出来的

Employee.select("employees.*").joins(:clients).group("employees.id").having("count(clients.id) > ?", n)