ruby on rails - Ambiguous table reference -

this problem seems simple, i've never encountered 1 this.

here settings:

post has_many :reader_links post has_many :readers, :through => :reader_links 

i need find out if there readers reading post.

@post.reader_links.where('created_at >= ?', 45.minutes.ago).any?

works great.

@post.readers.where('created_at >= ?', 45.minutes.ago),any?

throws ambiguous table column error because it's confused whether created_at column means of reader object or reader_link object. happens because class of reader user. how query readers created reader_links 45 minutes ago?

i'm looking like..

@post.readers.where('reader_link.created_at >= ?', 45.minutes.ago)

if right, need specify created_at column you're talking about:

@post.readers.where('reader_links.created_at >= ?', 45.minutes.ago).any?