activerecord

问题 Ok, this has me wildly stumped. I have a model PhoneNumbers which has an integer column sent_messages_count . I use background tasks to use this column as a counter cache, however, this column's inaccuracies appears to be more fundamental. Here's what I'd like to do: phone_number.sent_messages_count = phone_number.sent_messages.count Note that I'm setting the table column to the count of an association. Underscore vs. period. See my console session... (I've done some clean-up to make it more

问题 I have a double nested form: <%= simple_form_for @item, html: { class: "create-item-form" } do |item_builder| %> <div class="well"> <%= item_builder.input :name, required: false, error: false, label: "item name" %> <%= item_builder.input :description, as: :text, required: false, error: false, label: "How do users earn this item?" %> <%= item_builder.input :tag_list, required: false, label: "Tags (these will help users find your item)" %> <%= item_builder.simple_fields_for :user_items do |user

问题 I have the following semi-advanced DB query that is going through hourly prices for the last 10 years and returning daily average prices for the last seven days: averages = Trade.where('date >= ?', 7.days.ago).average(:price, :group => "DATE_TRUNC('day', date - INTERVAL '1 hour')") This returns the date (for that day) and an averageprice like this: "2012-12-29 00:00:00"=>#<BigDecimal:7f97932be328,'0.2513458333 33333333E2',27(27)> I then loop through each response and save them as new records

问题 I have a product that has many variants, those variants have two attributes: Size and Color. I want to query for the Variant based on the two attributes I pass in - I got it to work with following: variants = Spree::Variant.joins(:option_values).where(:spree_option_values => {:id => size.id}, :product_id => prod.id).joins(:option_values) variant = variants.select{|v| v.option_values.include?(size)} From my understanding, the select method more or less iterates through the array, which is

问题 This is a follow up question to this one: How to select only part of json, stored in Postgres, with ActiveRecord Say I have a model User , which has a field of type json called settings . Let's assume that this field looks roughly like this: { color: 'red', language: 'English', subitems: { item1: true, item2: 43, item3: ['foo', 'bar', 'baz'] } } The difference to the question cited above is that I'd like to know how to exclude part of the json. So here, I want to select everything from

问题 I'm new to Ruby on Rails and I'm hung up on using Active Record callbacks. I know how to use them, but I'm trying to truly understand what is happening, and I'm not getting it. My confusion has to do with variable scopes in Ruby. Here is a simple Active Record class for a user with fields: email, password_hash, password_salt class User < ActiveRecord::Base attr_accessor :password before_save :encrypt_password #validation validates :password, :confirmation => true validates :email, :password,

问题 I have a problem, that I can't understand... In my project I has several models. I have channel that has many restreams and each restream has one provider (it's a polymorphic assosiation). So in code I replace one restream.provider with another, and in the end restream.provider has a value of nil . I tried to put a lot of testing output, so now I have such a result: in one of the controllers I have a code: puts channel.restreams.last.provider.to_json byebug Delayed::Job.enqueue

问题 In my initial Rails 4 app, I had the following models: User has_many :administrations has_many :calendars, through: :administrations has_many :comments Calendar has_many :administrations has_many :users, through: :administrations has_many :posts has_many :comments, through: :posts Administration belongs_to :user belongs_to :calendar Post belongs_to :calendar has_many :comments Comment belongs_to :post belongs_to :user I just added a new Ad model to the app: Ad belongs_to :calendar And now I

问题 I'm getting this error when trying to instantiate too much objects in memory. This a Rails 2.3.x app, with SQL Server as the database. >> Shop.count => 14111 >> Shop.all ActiveRecord::StatementInvalid: ArgumentError: negative string size (or size too big): SELECT * FROM [shop] from /Users/lunks/.rvm/gems/ree-1.8.7-2011.03@ums/gems/activerecord-2.3.14/ lib/active_record/connection_adapters/abstract_adapter.rb:227:in `log' from /Users/lunks/.rvm/ gems/ree-1.8.7-2011.03@ums/gems/activerecord

问题 I have the following models role.rb class Role < ActiveRecord::Base attr_accessible :description, :user_id, :role_ids, :permission_ids, :permissions has_many :assignments has_many :users, :through => :assignments has_many :permissions validates :description, presence: true, uniqueness: true end permission.rb class Permission < ActiveRecord::Base attr_accessible :action, :role_id, :subject_class, :subject_id, :role belongs_to :role, :polymorphic => true end My roles_controller.rb is as follows