Mysql Error

Hello. I was working on a add friend function. Buts i get an mysql
error.

Mysql::Error: #23000Column 'created_at' in order clause is ambiguous:
SELECT `users`.id FROM `users` INNER JOIN friendships ON users.id =
friendships.friend_id WHERE (`users`.`id` = 2) AND
((`friendships`.user_id = 1) AND ((status = 'requested'))) ORDER BY
created_at LIMIT 1

Extracted source (around line #9):

6: form_tag "/#{controller.controller_name}/#{logged_user ?
'logout' : 'login'}" do %>
7:
8: <% if logged_user %>
9: <% unless @user == current_user ||
current_user.requested_friends.include?(@user) ||
current_user.friends.include?(@user) ||
current_user.pending_friends.include?(@user) %>
10: <% form_for(:friendship, :url => user_friends_path(:user_id =>
current_user.id, :friend_id => @user.id)) do |f| %>
11: <%= submit_tag "Lägg till som vän" %>
12:

Hello. I was working on a add friend function. Buts i get an mysql
error.

Mysql::Error: #23000Column 'created_at' in order clause is ambiguous:
SELECT `users`.id FROM `users` INNER JOIN friendships ON users.id =
friendships.friend_id WHERE (`users`.`id` = 2) AND
((`friendships`.user_id = 1) AND ((status = 'requested'))) ORDER BY
created_at LIMIT 1

well at the point where you've written :order => 'created_at' you need
to say 'users.created_at' or 'friendships.created_at'

Fred