Sorting a Rails active record

Question

I have a table A(:name, :address, :country_id) . I run this query

ids = [1,2,3]
@result = A.where(country_id: ids)

But, I want to get the results in this order : records containing country_id = 2 first, then 1 and then 3 .

How should I write this query?

Edit :

@people = []
@result.each do |r|
  @people.push([r,r.name])
end

I have an array @people of arrays now and want to sort it. What should be the query now?

Another Edit :

@people.sort_by! {|p| preferred_order.index(p.first.country_id)}

This worked.

Answer 1

You can use sort_by :

ids = [1,2,3]
preferred_order = [2,1,3]

@result = A.where(country_id: ids)
@result.sort_by! { |u| preferred_order.index(u.country_id) }

Answer 2

One option would be adding an extra column

 rails g migration add_sortorder_to_A sort_order:integer

Then add a

before_save :update_sort_order

def update_sort_order
  if self.country_id == 1
    self.update_attributes(sort_order:2)
  elsif self.country_id ==2
    self.update_attributes(sort_order:1)
 ........
end

Alternatively, put your sort_order in the countries and sort on that.

Alternatively, create a dynamic field which will give you the sort_order.

There is probably a more elegant way of doing this, but this should work in a quick and dirty way and allow you to use standard activerecord queries and sorting. (ie you can just forget about it once you've done it the once)