Given is a User Model who has_many Projects.
each Projects belongs_to a User
joined by a Assigned_projects Model
each Project has_many Expenses which belongs to a Project and a User
User Model:
class User < ActiveRecord::Base
has_many :assigned_projects
has_many :projects, :through => :assigned_projects
has_many :created_projects, :class_name => "Project", :foreign_key => :creator_id
end
Project Model:
class Project < ActiveRecord::Base
belongs_to :user
has_many :assigned_projects
has_many :users, :through => :assigned_projects
belongs_to :creator, :class_name => "User", :foreign_key => :creator_id
has_many :expenses
end
join Model:
class AssignedProject < ActiveRecord::Base
attr_accessible :project_id, :user_id, :position, :project
belongs_to :user, class_name: "User"
belongs_to :project, class_name: "Project"
validates :user_id, presence: true
validates :project_id, presence: true
end
Expenses Model:
class Expense < ActiveRecord::Base
belongs_to :project
belongs_to :user
end
Sum all Expenses of a project is easy:
#current_project.expenses.sum(:amount)
I want to list the sum of all Expenses each User added.
The Question is how to sum all Expenses for each user who is assigned to the Project.
I'am looking for something like:
#current_user.#current_project.expenses.sum(:amount)
I assume you are trying to do the following. If not, please explain your question a bit more.
#current_project.expenses.where(user_id: #current_user.id).sum(:amount)
Related
My db schema:
tournaments(id, ...)
teams(tournament_id, id, ...)
matches(tournament_id, id, team_id_home, team_id_away, ...)
Models:
class Tournament < ActiveRecord::Base
has_many :teams, dependent: :destroy
has_many :matches, dependent: :destroy
...
end
class Team < ActiveRecord::Base
belongs_to :tournament
...
end
class Match < ActiveRecord::Base
belongs_to :tournament
has_many :teams
...
end
I would like to have the following data in my view:
match_id team_id_home team_id_away team_id_home_name team_id_away_name
So, I'm asking for help with the following query (I'm trying to get team's names, but having problem with joining):
#matches = #tournament.matches.where(:tournament => #tournament).joins(:teams).paginate(page: params[:page])
I'm fairly new to rails, but you should be able to setup your associations like this: (going from memory)
class Match < ActiveRecord::Base
belongs_to :tournament
has_one :home_team, :class_name => "Team", :foreign_key => "team_id_home"
has_one :away_team, :class_name => "Team", :foreign_key => "team_id_away"
end
#####
m = Match.first
m.away_team.team_name
m.home_tam.team_name
Or in your case:
#matches = #tournament.matches.paginate(page: params[:page])
I don't think you need the where function: the has_many association tells rails to only pull matching matches.
It is belongs_to, not has_one in Match model.
class Match < ActiveRecord::Base
belongs_to :tournament
belongs_to :home_team, :class_name => "Team", :foreign_key => "team_id_home"
belongs_to :away_team, :class_name => "Team", :foreign_key => "team_id_away"
end
class Team < ActiveRecord::Base
belongs_to :tournament
has_many :matches
end
Now I can use tournament.home_team.name in my view
I have Board model. Each Board can be Source for other Board. This relationship is saved in Feed table.
class Board < ActiveRecord::Base
belongs_to :user
has_many :links, dependent: :destroy
has_many :feeds, dependent: :destroy
has_many :sources, through: :feeds
attr_accessible :description, :name, :user_id
validates :name, presence: true
end
class Feed < ActiveRecord::Base
belongs_to :board
belongs_to :source, class_name: "Board"
attr_accessible :board_id, :source_id
end
When I destroy Board record, then it destroys corresponding feeds. But how to do this the same but for source ?
Why don't you use :dependent => :destroy too?
Read Deleting from associations: has_many, has_one and belongs_to associations support the :dependent option
If that doesn't work you might also be able to use a ActiveRecord Callbacks:
after_destroy do |record|
other = BoardsSources.find_by_board_id_and_source_id(record.board_id, record.source_id)
other.destroy if other
end
i have the following models
class Airplane < ActiveRecord::Base
has_many :airtags
has_many :pictures, :through => :airtags
end
class Airtag < ActiveRecord::Base
attr_accessible :airable_type, :airable_id, :airplane_id
belongs_to :airplane
belongs_to :airable, :polymorphic => true
end
class Picture < ActiveRecord::Base
belongs_to :picturable, :polymorphic => true
has_many :airtags, :as => :airable, :dependent => :destroy
has_many :airplanes, :through => :airtags
end
in my airplane show, i want to list all pictures, ordered by their name.
#airplane.pictures.order(:name)
I have a User model and a Project model joined with the Ownership model using has_many :through. I am trying to set an Ownership attribute's value as I create an association between a User and a Project by using accepts_nested_attributes_for.
Here is my User model:
class User < ActiveRecord::Base
attr_accessible :name, :email, :admin, :projects
has_many :ownerships
has_many :projects, :through => :ownerships
accepts_nested_attributes_for :projects
Here is my ownership model:
class Ownership < ActiveRecord::Base
attr_accessible :owner_type
belongs_to :project
belongs_to :user
validates :user_id, :presence => true
validates :project_id, :presence => true
validates :owner_type, :presence => true
end
and my project model:
class Project < ActiveRecord::Base
attr_accessible :name, :description
has_many :ownerships
has_many :users, :through => :ownerships
and this is how I'm trying to set the owner_type value of the ownership model as its being created:
current_user.ownerships.create(:owner_type => 'designer', :project => #project)
for some reason this isn't creating the ownership join model or (obviously) setting the owner_type value of the ownership model. What can I do to fix this?
I have the following models:
class User < ActiveRecord::Base
has_many :books, :dependent => :destroy
has_many :favorites
has_many :books, :through => :favorites
end
class Favorite < ActiveRecord::Base
belongs_to :book
belongs_to :user
validates :user_id, :book_id, :presence => true
end
class Book < ActiveRecord::Base
belongs_to :user
belongs_to :favorite
end
The idea is that a user can own a book and add a book from another user as favorite. In rails console, i tried User.find(1).favorites.books but got a NoMethodError: undefined method books'. Anduser.books` only returns the books owned by that user
Is there any way to retrieve all books that belong to a user's favorite in this case?
You are very close, but you shouldn't have two associations name books. Try something like this:
class User < ActiveRecord::Base
has_many :books, :dependent => :destroy
has_many :favorites
has_many :favorite_books, :through => :favorites, :source => :book
end
Then your query would simply be User.find(1).favorites_books