You can convert an array of objects arr to an ActiveRecord::Relation like this (assuming you know which class the objects are, which you probably do) MyModel.where(id: arr.map(&:id)) You have to use where though, it’s a useful tool which you shouldn’t be reluctant to use. And now you have a one-liner converting an array to a … Read more
1) To get Projects with at least 1 vacancy: Project.joins(:vacancies).group(‘projects.id’) 2) To get Projects with more than 1 vacancy: Project.joins(:vacancies).group(‘projects.id’).having(‘count(project_id) > 1’) 3) Or, if Vacancy model sets counter cache: belongs_to :project, counter_cache: true then this will work, too: Project.where(‘vacancies_count > ?’, 1) Inflection rule for vacancy may need to be specified manually?
Your placeholder is replaced by a string and you’re not handling it right. Replace “name LIKE ‘%?%’ OR postal_code LIKE ‘%?%'”, search, search with “name LIKE ? OR postal_code LIKE ?”, “%#{search}%”, “%#{search}%”
If you are using the Rails 4.x you can now generate migrations with references, like this: rails generate migration AddUserRefToProducts user:references like you can see on rails guides
You are right. If you want to delete the User and all associated objects -> destroy_all However, if you just want to delete the User without suppressing all associated objects -> delete_all According to this post : Rails :dependent => :destroy VS :dependent => :delete_all destroy / destroy_all: The associated objects are destroyed alongside this … Read more
In Postgres you can do: @user.comments.group(“DATE_TRUNC(‘month’, created_at)”).count to get: {“2012-08-01 00:00:00″=>152, “2012-07-01 00:00:00″=>57, “2012-09-01 00:00:00″=>132} It accepts values from “microseconds” to “millennium” for grouping: http://www.postgresql.org/docs/8.1/static/functions-datetime.html#FUNCTIONS-DATETIME-TRUNC
Figured it out, the task should look like: namespace :test do task :new_task => :environment do puts Parent.all.inspect end end Notice the => :environment dependency added to the task
From the documentation: set() will also accept an optional third parameter ($escape), that will prevent data from being escaped if set to FALSE. So this should work to pass the increment statement directly to the database: $this->db->set(‘usage’, ‘usage+1’, FALSE); $this->db->where(‘tag’, ‘java’); $this->db->update(‘tags’); Because it’s not escaped, if you’re using a variable instead of a fixed … Read more
You can use validates_presence_of http://apidock.com/rails/ActiveModel/Validations/ClassMethods/validates_presence_of class A < ActiveRecord::Base has_many :bs validates_presence_of :bs end or just validates http://apidock.com/rails/ActiveModel/Validations/ClassMethods/validates class A < ActiveRecord::Base has_many :bs validates :bs, :presence => true end But there is a bug with it if you will use accepts_nested_attributes_for with :allow_destroy => true: Nested models and parent validation. In this topic you … Read more
How it actually works is that the association object is a “proxy object”. The specific class is AssociationProxy. If you look at line 52 of that file, you’ll see: instance_methods.each { |m| undef_method m unless m =~ /(^__|^nil\?$|^send$|proxy_|^object_id$)/ } By doing this, methods like class no longer exist on this object. So if you call … Read more