User
#
Cars
belongs_to :father, :class_name => "User"
belongs_to :user
user = User.find(1)
Guys help I can get the user's cars by typing user.cars (searches cars using user_id) but how exactly can I get it to search using father_id?
Obviously I can do a Car.find_by_creator_id(...) but I wanted to know if there was a railish solution.
Thanks
You can set up the other side of the relations and specify :inverse_of for each in the User model. Something like
class User < ActiveRecord::Base
has_many :father_cars, :class_name => "Car", :inverse_of => :father
has_many :cars, :inverse_of => :user
# ...
end
Cars < ActiveRecord::Base
belongs_to :father, :class_name => "User", :inverse_of => :father_cars
belongs_to :user, :inverse_of => :cars
# ...
end
You can then access the :father relation with
u = User.find(1)
cars = user.father_cars
Related
I am trying to select groups which the #current_user is NOT a member of
The relevant parts of my models are as follows:
class Group < ActiveRecord::Base
belongs_to :user
has_many :group_memberships
has_many :members, :class_name => "User", :through=>:group_memberships
...
class User < ActiveRecord::Base
has_many :group_memberships, :foreign_key => 'member_id'
has_many :groups, :through => :group_memberships
...
class GroupMembership < ActiveRecord::Base
belongs_to :member, :class_name=>"User"
belongs_to :group
end
Thanks!
You could try and do something like:
#groups = Group.where("id NOT IN (?)", current_user.groups)
More information can be found in the Active Record Query.
have a method like this:
def group_ids_not_a_member_of
# get all group_ids and subtract out the ids that he is a member of
Group.pluck('id') - current_user.groups.map(&:id)
end
then
user.group_ids_not_a_member_of
I have a has_many through relationship between Course and User.
class Course < ActiveRecord::Base
belongs_to :user
has_many :enrollments, :dependent => :delete_all
has_many :users, :through => :enrollments
attr_accessible :description, :duration, :name, :prerequisites, :short_name, :start_date, :user_id
accepts_nested_attributes_for :users, :allow_destroy => true
attr_accessible :users_attributes
and User:
class User < ActiveRecord::Base
has_many :subjects, :class_name => "Course" # to get this call user.subjects
has_many :enrollments, :dependent => :delete_all
has_many :courses, :through => :enrollments
and Enrollment:
class Enrollment < ActiveRecord::Base
belongs_to :course
belongs_to :user
attr_accessible :course_id, :user_id
end
Now I'm trying to set user_ids from inside Course, using a nested form. It keeps giving me that Mass Assignment warning, and nothing is saved. I read I was supposed to add attr_accessible user_id but it still doesn't work.
Even if I do something like this from the rails console:
#c.update_attributes({:user_ids => [7,8]})
with #c being the course
Any help would be greatly appreciated,
Thank you.
It's user_ids, not user_id.
You need to add user_ids to your attr_accessible.
I have an app that lets users input dates & interests that relate to those dates .I need to send them deals (a few days before the date - Via Email) that are based off of their interests and location. I have all the models setup and recording the data properly, just wondering how to query the models for the dates and then send the appropriate deal based off of the city and interests.
Notes:
*Each city and interest category has only 1 deal
*I have several different models for types of dates (Holidays, Occasions, Friends Birthdays ect).. all are pretty much identical in structure.
*All interests for each type of date are stored in person_interests.
Models:
Class User
belongs_to :province
belongs_to :city
has_many :friends_bdays
has_many :occasions
has_many :person_interests, :as => :person
has_many :interests, :through => :person_interests
has_many :user_holidays
has_many :holidays, :through => :user_holidays
has_many :anniversaries
end
class Deal < ActiveRecord::Base
belongs_to :interest
belongs_to :city
belongs_to :store
end
class Store < ActiveRecord::Base
has_many :deals
belongs_to :city
belongs_to :province
end
class PersonInterest < ActiveRecord::Base
belongs_to :interest
belongs_to :person, :polymorphic => true
end
class Interest < ActiveRecord::Base
has_many :person_interests
has_many :deals
end
class Occasion < ActiveRecord::Base
belongs_to :user
belongs_to :admin_user
has_many :person_interests, :as => :person
has_many :interests, :through => :person_interests
end
class Anniversary < ActiveRecord::Base
belongs_to :user
has_many :person_interests, :as => :person
has_many :interests, :through => :person_interests
end
class Friend_bday < ActiveRecord::Base
belongs_to :user
has_many :person_interests, :as => :person
has_many :interests, :through => :person_interests
end
You can achieve this using a variation of the solution below:
Install the squeel gem
class User
def deals(reload=false)
#deals = nil if
#deals ||= Deal.where{
( (:city => city_id) | ( :interest_id => interest_ids) ) &
:deal_date => (Time.now..3.days.from_now)
}
end
end
Now, user.deals returns the deals that will be active in next 3 days matching the user's city OR interests.
Edit 1:
Based on your comment it looks like you don't need the squeel gem. You can achieve what you want using regular AR syntax.
class User
def deals(reload=false)
#deals = nil if reload
#deals ||= Deal.where(
:city => city_id,
:interest_id => interest_ids,
:deal_date => (Time.now..3.days.from_now)
)
end
end
I have an accounts model as follows (simplified):
class Account < ActiveRecord::Base
attr_accessible :account_number, :display_name, :master_account_id
has_many :child_accounts, :class_name => "Account", :foreign_key => "id"
belongs_to :master_account, :class_name => "Account", :foreign_key => "master_account_id"
end
#account.master_account is currently working correctly, but I also want to be able to access #account.child_accounts - what do I need to do in order to fix that?
I think it has to be the other way round:
class Account < ActiveRecord::Base
has_many :child_accounts, :class_name => "Account", :foreign_key => "master_account_id"
belongs_to :master_account, :class_name => "Account"
end
Warning:Total Rails Newb (TRN). This should be a pretty basic question so I'm hoping someone can spare a couple mins to help shed some light.
Let's say I have the following models: User, Group, and Member
A user can have many groups (let's say friends, family, etc)
A group can have many members, namely other users.
How would I structure this?
Initially I tried this:
class User < ActiveRecord::Base
has_many :groups
has_many :groups, :through => :members
end
class Groups < ActiveRecord::Base
has_many :users, :through => :members
belongs_to :user
end
class Member < ActiveRecord::Base
belongs_to :group
belongs_to :user
end
However this gave me an error in User so I changed
has_many :groups, :through => :members
to
has_many :memberships, :through => :members, :source => :groups
Still getting an error about missing association when I try to do
group = Group.new
group.user.new
It will be useful: http://railscasts.com/episodes/47-two-many-to-many
class User < ActiveRecord::Base
has_many :members
has_many :groups, :through => :members
has_many :groups_as_owner, :class_name => "Group"
end
class Groups < ActiveRecord::Base
has_many :members
has_many :users, :through => :members
belongs_to :owner, :class_name => "User", :foreign_key => :user_id
end
class Member < ActiveRecord::Base
belongs_to :group
belongs_to :user
end
basically has_many-through associations are n:m associations (join-tables) that (shall) have more attributes than just the id's of the joined record ids...
so you have a table Groups (with an id), a table Users (with an id) and a table Members (no id, but user_id and group_id)
basically, what you did is nearly correct, just think about how you access a group from a user or vice versa....
a user would first look up its member information and through that member information get access to the group information ... and vice versa for a group
so you first set up
has_many :members
and then call
has_many :groups, :through => :members
all you need is
class User < ActiveRecord::Base
has_many :members
has_many :groups, :through => :members
end
class Groups < ActiveRecord::Base
has_many :members
has_many :users, :through => :members
end
class Member < ActiveRecord::Base
belongs_to :group
belongs_to :user
end
and you have another bug in your code above
you might want to use
user = group.users.new
instead of
user = group.user.new
Try this structure:
class User < ActiveRecord::Base
has_many :members
has_many :groups, :through => :members
end
class Groups < ActiveRecord::Base
has_many :members
has_many :users, :through => :members
end
class Member < ActiveRecord::Base
belongs_to :group
belongs_to :user
end
Also take a look at has_and_belongs_to_many, if you don't need to do with class Member then you should use has_and_belongs_to_many. In this case don't forget to create joining table in the database