ruby - Rails - multiple association unknown attribute -

i'm making api in rails, , has model called match has 2 association user model defined as

belongs_to :user_a, class_name: 'user', foreign_key: 'user_a' belongs_to :user_b, class_name: 'user', foreign_key: 'user_b' 

in user model:

has_many :matches 

in match controller spec, i'm doing following:

before(:each)     user = factorygirl.create :user     api_authorization_header user.auth_token     @match_attribs = factorygirl.attributes_for :match     post :create, { match: @match_attribs } end 

and tests fails "unknown attribute: user_id"

if make change post:

post :create, { user_a: user.id, user_b: user.id, match: @match_attribs } 

then still giving me unknown attribute.

edit: scheme matches:

create_table "matches", force: true |t|     t.integer  "user_a"     t.integer  "user_b"     t.datetime "created_at"     t.datetime "updated_at" end  add_index "matches", ["user_a"], name: "index_matches_on_user_a" add_index "matches", ["user_b"], name: "index_matches_on_user_b" 

thanks help

rails , sql convention dictate foreign keys should end in _id, e.g. user_a_id, user_b_id. since rails built around "convention on configuration," convention make code simpler. if change field names, code becomes:

match.rb

belongs_to :user_a, class_name: "user" belongs_to :user_b, class_name: "user" 

user.rb

has_many :matches_a, class_name: 'match', foreign_key: 'user_a_id' has_many :matches_b, class_name: 'match', foreign_key: 'user_b_id'  def matches   match.where("user_a_id = :id or user_b_id = :id", id: id) end 

using method way make kind of relation. way return relation can further query, while concatenating other 2 relations (matches_a + matches_b) return array.