CODEWITHSUNDEEP
ruby-on-railsrubyactiverecord
Jason Attwood
Jason Attwood

Reputation: 59

Ruby on rails ActiveRecord Relation not working?

I have an issue where my ActiveRecord::Relation isn't working I have 3 Db's Users,Games,Achievements The relation defined between them is such

Users 

has_many :games

Games

belongs_to :user
has_many :achievements

Achievements

belongs_to :game

The problem is when i try to call 

Game.where(:appid => game["appid"]).achievements.new

it gives me and error saying that 

undefined method `achievements' for #<Game::ActiveRecord_Relation:0x730f9f8>

I am running on Ruby on Rails 4.1.8 and I have no clue why this is happening (I do have the belongs_to :game,index: true column in my Achievements table I can't think of why its not working)

Upvotes: 1

Views: 1394

Answers (3)

joem
joem

Reputation: 331

The answer is in the exception. #where returns an ActiveRecord_Relation, not a Game, even if there is only one Game in the relation. So you really have an enumerable. i.e:

puts Game.where(:appid => game["appid"]).first.achievements.new

If you just want the first game that meets the criteria, you can use find_by

Game.find_by(:appid => game["appid"])

but I am not sure that's what you are looking for

Upvotes: 0

Alexander Kireyev
Alexander Kireyev

Reputation: 10825

Probably, you should select one model 

Game.where(:appid => game["appid"]).first

and then get relational models

.achievements.new

Upvotes: 0

jjk
jjk

Reputation: 536

You are getting an association here:

 Game.where(:appid => game["appid"])

... this is realized as an array of objects (even if the sql returns no records, then it is still an array, although it is empty).

You need to select one of them ... probably the first, like this:

 Game.where(:appid => game["appid"]).first.achievements.new

Or you can run through the values:

 Game.where(:appid => game["appid"]).each { |game| game.achievements.new }

or some such.

Upvotes: 1

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