Create an array from database rails

Question

i need help with the following topic:

I'm trying to create an array of users based on their ids

  def show
    @appointment = Appointment.where(:event_id => :id).all
    @users = Array.new
    @appointment.each do |appointment|
      @users.fill(User.find(appointment.user_id))
    end

  end

First, im getting all appointments which event_id are the same to :id (which comes from the Event table) . Then i proceed to create an array to be filled later with users inside the .each do expression.

The problem is that @users is empty after the expresion ends.

What am i doing wrong?

BroiSatse · Accepted Answer · 2015-06-24 23:53:36Z

2

Much simpler:

@users = User.find(Appointment.where(event_id: <id>).pluck(:id))

Your code does not work as you misunderstood what method fill does - it substitutes all elements of the array with passed object (pretty much like this, might take some extra params to alter its behaviour a little bit). You were most liekly looking for push or unshift methods.

Much better solution

If I am correct, your associations most likely looks like this:

Event has_many :appointments
Appointment belongs_to :user

n that case, you can simply create has_many :through association:

class Event < ActiveRecord::Base
  has_many :appointments
  has_many :users, through: :appointments
end

Then your query is just:

Event.find(<id>).users

edited Jun 24, 2015 at 23:53

answered Jun 24, 2015 at 23:47

BroiSatse

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Comments

Prakash Murthy · Accepted Answer · 2015-06-24 23:52:27Z

0

@users = Appointment.includes(:user).where(:event_id => <id>).map(&:user)

should work, assuming you have the User has_many :appointments & Appointments belongs_to :user associations setup.

edited Jun 24, 2015 at 23:52

answered Jun 24, 2015 at 23:48

Prakash Murthy

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Create an array from database rails

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