Question

I’m still a newbie with Rails (and actually development period). I’m using Rails 3.

activity has these fields: id, user_id, activity_type (integer).

In my view, I want to show a count of each activity type the user has done, something like this:

 <%= activity.activity_type %> - [count for activity]

Only, I can figure out how to do it. In my controller, I tried different things like:

@user = current_user

@activity_type_ids = Activity.select("DISTINCT(activity_type_id)")
@activity_type_counts = Activity.where('user_id = ? and activity_type_id = ?', @user.id, @activity_type_ids).count   

or

@activity_type_counts = Activity.where('user_id = ? and activity_type_id = ?', @user.id, @activity_type_ids).group("activity_type_id").count   

In my view, I’ve tried:

<% @activity_type_counts.each do |activity_type_count| %>
  <%= "(#{activity_type_count.activity_type_id}) #{activity_type_count}" %>
<% end %>

and

<% @activity_type_ids.each do |activity_type_id| %>
  <%= "(#{activity_type_id.activity_type_id}) #{@activity_type_count}" %>
<% end %>

Thank you in advance for any help you can provide!

---

updated with models and controller
fixing the model details

I have three models: user, location and activity. A user has many locations. A location can have many activities.

user.rb

has_many :locations 

location.rb

belongs_to :user
has_many :activities

activities.rb

belongs_to :location 

activity_report_controller

@user = current_user
@locations = @user.locations
@activities = @locations.activities.count(:group => "activity_type_id")

Answer 1

I assume you have

class User
  has_many :activities
end

Then you can just say

@user.activities.count(:group => "activity_type_id")

This should return an OrderedHash with the keys as the ids and the values as the counts.

---

UPDATE: turns out the original question was wrong, there is an intermediary Location

What you want is a has many through on user to activities

class User
  has_many :locations 
  has_many :activities, :through => :locations
end

class Location
  has_many :activities
end

Now in your controller.

@user = current_user
@activity_counts = @user.activities.count(:group => "activity_type_id")