Choosing a specific row in a table in rails

Question

I have a migration and model with a table called medications. I need to pick a specific row from the medications table. I also am trying to filter out all medications that don't have the current user's id.

Here is the current code I have.

Medication.find(:name, :conditions => { :user_id => current_user.id }, :order => "Medication.name")

I know this isn't complete, but any help would be greatly appreciated.

Answer 1

You can load the first medication for a specific user_id like this (assuming that your medications table has an user_id):

Medication.where(user_id: current_user.id).order(:name).first

When our User model has a belongs_to :medications it can be simplified to:

current_user.medications.order(:name).first

When you want to load the e.g. 5th medication just add an offset of 4:

current_user.medications.order(:name).offest(4).first

Or load all medications and iterate through them:

current_user.medications.limit(10).each do |medication|
  puts medication.name
end

When you want to output the first ten medications on a website you would do something like this:

# in the controller
@medications = current_user.medications.order(:name).limit(10)

# in the view
<ul>
  <% @medications.each do |medication| %>
    <li><%= medication.name %></li>
  < end %>
</ul>

The finder syntax you use is deprecated and was replaced in Rails 4. See Rails Guide about querying the database.