has-and-belongs-to-many

问题 I'm managing my admin backend with Typus I want to add a field with a checkbox for each category. I used this code: Post: fields: default: name, description, user, categories list: name, description, user, categories form: name, description, user, categories relationships: categories But the result is a textfield with a [] inside: how do I solve this? Is there a native way or must I override the field template? 回答1: To show the the checkbox for the fields you can use the existing template of

问题 I have 2 models. Category and Post. They are connected using a has_many_and_belongs_to_many relationship. I checked in the rails console and the relationship works. I created checkboxes in activeadmin to set the post categories using this form field: f.input :categories, as: :check_boxes, collection: Category.all The problem is when I try to save it because every other field data (title, body, meta infos etc.) is saved, but the category stays the same even if I unchecked it, or checked

问题 I have a form that's got the following association: Course.rb has_and_belongs_to_many :skills Skill.rb has_and_belongs_to_many :courses what I wanna do is allow the person who wants to add a new Course select all the skills from his selected category and be able to add them by using a checkbox. In the view I've done like so: VIEW <%= form_for(@course) do |f| %> <% @skills.each do |s| %> <%= f.check_box :value => s.id %> <%= s.title %><br /> <% end %> <% end %> Sadly this isn't working and I

问题 I have a form that's got the following association: Course.rb has_and_belongs_to_many :skills Skill.rb has_and_belongs_to_many :courses what I wanna do is allow the person who wants to add a new Course select all the skills from his selected category and be able to add them by using a checkbox. In the view I've done like so: VIEW <%= form_for(@course) do |f| %> <% @skills.each do |s| %> <%= f.check_box :value => s.id %> <%= s.title %><br /> <% end %> <% end %> Sadly this isn't working and I

问题 So Rails doesn't have support for :through associations through a habtm relationship. There are plugins out there that will add this in for Rails 2.x, but I'm using Rails 3 / Edge, and only need the association for one particular model. So I thought I'd stump it out myself with the beauty that is Arel. First, the models: class CardSet < ActiveRecord::Base has_and_belongs_to_many :cards, :uniq => true end class Card < ActiveRecord::Base has_and_belongs_to_many :card_sets, :uniq => true has

问题 I'm using Devise for user registration. I've been reading the all famous tutorial about customizing Devise, but can't understand this simple task. I followed his model (HABTM) I want to add a roles check box to the Devise edit form. I don't have a Controller cause Devise doesn't provide one, but managed to add a default role to new users. I was able to display the checkboxes with the correct info checked but can't edit it (it won't save anydata). Do I need a custom controller? if yes, how

问题 I have next 'member_companies' table in DB: And in model Member has a relation : public function companies() { return $this->belongsToMany(Company::class, 'member_companies'); } And it return me all companies with dublicates. For example, Member::find(238)->companies->pluck('id') return [ 6, 5, 7, 2, 10, 8, 4, 13, 14, 10, 8, 13 ] But I want only unique items. Like [ 6, 5, 7, 2, 10, 8, 4, 13, 14, ] How can I do it with eloquent relations? 回答1: You should use the unique() method in your

问题 I've found an old plugin called acts_as_habtm_list - but it's for Rails 1.0.0. Is this functionality built in acts_as_list now? I can't seem to find any information on it. Basically, I have an artists_events table - no model. The relationship is handled through those two models specifying :has_and_belongs_to_many How can I specify order in this situation? 回答1: I'm assuming that you have two models - Artist and Event. You want to have an habtm relationship between them and you want to be able

问题 I'm using cakephp and would like to display all Submissions which are part of Category 'X' I have 4 tables with a HABTM relationship. Users -> (haveMany) -> Submissions <-> (hasAndBelongsToMany) <-> Categories but I would like to do so using the $this->paginate() and for each submission I would like to display the user who posted the submission. User Table Id | Name -----+------------------- 1 | User 1 2 | User 2 Submission Table Id | Name | User_id -----+-------------------+-------------- 1

问题 I'm using cakephp and would like to display all Submissions which are part of Category 'X' I have 4 tables with a HABTM relationship. Users -> (haveMany) -> Submissions <-> (hasAndBelongsToMany) <-> Categories but I would like to do so using the $this->paginate() and for each submission I would like to display the user who posted the submission. User Table Id | Name -----+------------------- 1 | User 1 2 | User 2 Submission Table Id | Name | User_id -----+-------------------+-------------- 1