Question

I want to select users from the users table based on:

user.created
user.sales_count

So I want to fetch all users, sometimes ordered by created date, and sometimes based on sales_count. And I want to be able to switch between ASC or DESC order.

All queries need to have this WHERE clause:

WHERE region = 123

How can I build my active record query to support these order by conditions?

Answer 1

def get_users(options={})
  options[:order_col] ||= "created"
  options[:order_type] ||= ""
  User.where(:region=>123).order("#{options[:order_col]} #{options[:order_type]}")
end

options[:order_col] ||= is really saying:

options[:order_col] = options[:order_col] || ""

which in english is saying set options[:order_col] to options[:order_col] if set, other wise "". We can set the order_type to "" because SQL will by default order results ASC.

Example:

get_users #=> return ordered by created ASC
get_users(:order_col => "sales_count") #=> return order by sales count ASC
get_users(:order_col => "sales_count", :order_type => "DESC") #=> sales_count, DESC
# etc