Problems with associations

rubyonrails-talk
1

Hello guys, I have two tables, tasks and projects, and each model I put:

Task.rb

class Task < ActiveRecord::Base   attr_accessible :user_id, :project_id, :name   belongs_to :project end

Project.rb

class Project < ActiveRecord::Base   attr_accessible :name, :description   has_many :tasks end

But when I go to my prompt and I make a SELECT with task, none project is returned.

irb(main):001:0> Task.all   ←[1m←[36mTask Load (0.0ms)←[0m ←[1mSELECT `tasks`.* FROM `tasks` ←[0m   ←[1m←[35mEXPLAIN (30.0ms)←[0m EXPLAIN SELECT `tasks`.* FROM `tasks` EXPLAIN for: SELECT `tasks`.* FROM `tasks`

2

irb(main):001:0> Task.all

=> [#<Task id: 1, user_id: nil, project_id: 1, name: "W\r<br>T\r<br>F\r<br>VERY\r<br...", del eted: 0, done: 0, created_at: "2012-06-24 15:46:37", updated_at: "2012-06-30 17:13:27">, #<Task id: 2, user_id: nil, pro ject_id: 1, name: "Teste", deleted: 0, done: 0, created_at: "2012-06-30 17:11:27", updated_at: "2012-06-30 17:11:27">]

I guess the project name should come too ? right ?

Wrong.

What am I doing wrong ?

Misunderstanding ActiveRecord and associations :slight_smile:

Revisiting the relevant Rails guides might be a good idea.

3

Nothing. The project will only be fetched if you use :include in the query. However, for one of the tasks fetched above you can still say task.project and it will fetch the project then.

Colin

4

Hello Colin, thank you for your answer..

I tryed this:

irb(main):001:0> task = Task.all   ←[1m←[36mTask Load (1.0ms)←[0m ←[1mSELECT `tasks`.* FROM `tasks` ←[0m   ←[1m←[35mEXPLAIN (1.0ms)←[0m EXPLAIN SELECT `tasks`.* FROM `tasks` EXPLAIN for: SELECT `tasks`.* FROM `tasks`

5

irb(main):001:0> task = Task.all

Model.all is clearly intended to return multiple results; it would be more appropriate to say `tasks = Task.all`

irb(main):002:0> task.project NoMethodError: undefined method `project' for #<Array:0x482b068>

in which case you would be calling e.g.

tasks.first.project or tasks.each{ |task| puts task.project.inspect } or whatever

6

Thanks a lot Hassan, I tryed with tasks.first.project and everything is OK.

Thanks again.