associations

问题 I'm trying to get a nested form view to update properly. This is however causing problems when the second form has existing data. I'm using accepts_nested_attributes_for and nested_form_for. The second which only purpose is to dynamically add the form element using js. See github for more The error I'm getting is: Couldn't find Muscle with ID=3685340 for Exercise with ID=212831413 I've tried to manually do the updating but my code didnt really work and I'm under the impression that it

问题 I'm working on a Rails app that is a compendium of quotes that artists have said about other artists, and I'm having trouble figuring out how the relationships in my data model should work. Take this quote as an example. Here is something David Bowie said about Lou Reed: "He was a master" My attributes for a Quote model in this example would be something like this: Excerpt => "He was a Master" Speaker => "David Bowie" Subject => "Lou Reed" But what if Lou Reed said something about David Bowie

问题 I have the following models: class Test < ApplicationRecord end class Exam < Test end class Practice < Test has_many :relations has_many :questions, through: :relations end class Relation < ApplicationRecord belongs_to :practice belongs_to :question end class Question < ApplicationRecord has_many :relations has_many :practices, through: :relations end And this is my schema: create_table "questions", force: :cascade do |t| t.string "title" t.text "text" t.datetime "created_at", null: false t

问题 I have a question regarding apriori rule deployment in R. I basically want to assign a predcition(item) and a confidence value to each customer so I can create a simple recommending system, so below is a subset of my rule set which I have obtained, bread&wine -> meat (confidence 54%) cheese -> fruit (confidence 43%) bread&cheese -> frozveg (confidence 24%) and the following is simple representation of what I want to achieve with just 1 customer; this is in a basket or truth-table data. ID

问题 I am trying to use cocoon gem to build nested forms. I have models for Organisation, Package::Bip and Tenor. The associations are: Organisation has_many :bips, as: :ipable, class_name: Package::Bip accepts_nested_attributes_for :bips, reject_if: :all_blank, allow_destroy: true Package::Bip (polymorphic) belongs_to :ipable, :polymorphic => true, optional: true, inverse_of: :bip has_one :tenor, as: :tenor accepts_nested_attributes_for :tenor, reject_if: :all_blank, allow_destroy: true Tenor

问题 I am new to UML, and I don't quite understand the notation yet. This is my understanding of the diagram. The system has many doctors. Doctors can have many patients; however, patients can only have one doctor. Therefore this is a **One-To-Many** relationship However, I feel like this can also be interpreted as... The system has 1 doctor. That one doctor has many patients. Which is the correct interpretation and why? 回答1: To put it simply: your first interpretation is correct. Each Doctor is

问题 I wish to open a file (lets say, a word document) from a Java application using the associated program installed on the computer (in this example, using MS Word or Open Office Writer). The catch is that I want to wait until this subprocess finishes, which can be done using the waitFor() method in the Process class. String executable = findAssociatedApplicationPath(); //for example, returns "C:\\Program Files\\Microsoft Office\\Office12\\msword.exe" Process p = Runtime.getRuntime().exec

问题 Can I add some condition to the LEFT JOIN sql that Rails generate for the includes method? (Rails 4.2.1, postresql). I need to get all(!) the users with preloading ( not N+1 when I will puts in a view count of comments, posts and etc) of associations, but associations need to be filtered by some conditions. Example: User.includes(:comments) # => SELECT * FROM users LEFT JOIN comments ON ... This will return all the users and preload comments if they exists. If I will add some conditions for

问题 I am trying to make an app in Rails 4. I have a profile model, a qualification model, and a vision model. The associations are: profile.rb has_many :qualifications accepts_nested_attributes_for :qualification has_one :vision accepts_nested_attributes_for :vision qualification.rb belongs_to :profile vision.rb belongs_to :profile I have several other models in a similar construct as qualification and vision (ie. they belong to profile). All relevant attributes have been included in the strong

问题 I have Person model, it contains id, first_name, last_name etc and merital_id field. I also have Merital model contains only 2 field: id and title. Server responses JSON like: { success: true, items: [ { "id":"17", "last_name":"Smith", "first_name":"John", ... "marital_id":1, "marital": { "id":1, "title":"Female" } }, ... ] } So how can I connect my models with association? I still can use record.raw.merital.title in my column.renderer, but I cannot use such fields in templates like {last