rails - association params selected, but params "changing" on persist - mysql

Question

I really am not sure of how to describe this problem and I've never had an issue like this before. I am trying to set up a "has_many :through" association that handles membership requests to a group. The other actions (destroy, update) seem to be working fine. Whenever I initiate the create action in my controller, the object shows that it is being passed the correct params and the association is created. However, it is creating an association only to the group with the "1" id. I have no idea how to clearly explain this problem or solve it. I'll post my log and code below.
To clarify my question: why is the data "changing" when it persists to the database (on create)?
Cliqs = Groups
Log:
Started POST "/cliqs/2/cliq_requests" for ::1 at 2016-03-31 20:35:32 -0500
Processing by CliqRequestsController#create as HTML
Parameters: {"authenticity_token"=>"uaVHFgB7digMywl2a/n2GKMtwi691WA/dw2F2mzdkSCK69C46TZICiSp90xldj3hosFwSOPEi3fSOvOSkIVMjA==", "cliq_id"=>"2"}
Cliq Load (0.0ms) SELECT `cliqs`.* FROM `cliqs` WHERE (2) LIMIT 1
User Load (0.0ms) SELECT `users`.* FROM `users` WHERE `users`.`id` = 1 ORDER BY `users`.`id` ASC LIMIT 1
(0.0ms) BEGIN
SQL (1.0ms) INSERT INTO `cliq_requests` (`cliq_id`, `user_id`, `created_at`, `updated_at`) VALUES (1, 1, '2016-04-01 01:35:32', '2016-04-01 01:35:32')
(198.0ms) COMMIT
Redirected to http://localhost:3000/cliqs
Completed 302 Found in 237ms (ActiveRecord: 199.0ms)
Controller Action:
def create
#cliq = Cliq.find_by(params[:cliq_id])
#cliq_request = current_user.cliq_requests.new(cliq: #cliq)
if #cliq_request.save
redirect_to cliqs_path
else
redirect_to current_user
end
end
Other Actions (just in case):
def update
#cliq = Cliq.find_by(params[:cliq_id])
#cliq_request = CliqRequest.find(params[:id])
#cliq_request.accept
end
def destroy
#cliq = Cliq.find_by(params[:cliq_id])
#cliq_request = CliqRequest.find(params[:id])
#cliq_request.destroy
if #cliq_request.destroy
redirect_to cliqs_path
else
redirect_to current_user
end
end
And the Models:
class User < ActiveRecord::Base
has_one :owned_cliq, foreign_key: 'owner_id', class_name: 'Cliq', dependent: :destroy
has_many :cliq_memberships, dependent: :destroy
has_many :cliqs, through: :cliq_memberships
has_many :cliq_requests, dependent: :destroy
end
class Cliq < ActiveRecord::Base
belongs_to :owner, class_name: 'User'
has_many :cliq_memberships, dependent: :destroy
has_many :members, through: :cliq_memberships, source: :user
has_many :cliq_requests, dependent: :destroy
has_many :pending_members, through: :cliq_requests, source: :user, foreign_key: 'user_id'
end
class CliqRequest < ActiveRecord::Base
#from
belongs_to :user
#to
belongs_to :cliq
def accept
cliq.members << cliq.pending_members.find(user_id)
destroy
end
end
Finally my View:
<h1><%= #cliq.name %></h1>
<%= link_to 'Request to join Cliq', cliq_cliq_requests_path(#cliq, #cliq_request), :method => :post %>
<% #cliq_members.each do |cliq_member| %>
<ul><%= link_to cliq_member.username, user_path(cliq_member) %></ul>
<% end %>
<h3>Cliq Requests:</h3>
<ul>
<% #cliq.pending_members.each do |pending_member| %>
<%= link_to pending_member.username, user_path(pending_member) %>
<% end %>
<% #cliq.cliq_requests.each do |cliq_request| %>
<%= link_to "Accept", cliq_cliq_request_path(#cliq, cliq_request), :method => :put %>
<%= link_to "Deny", cliq_cliq_request_path(#cliq, cliq_request), :method => :delete %>
</ul>
<% end %>

Answer 1

As you found out yourself, using #cliq = Cliq.find_by(id: params[:cliq_id]) works, and #cliq = Cliq.find_by(params[:cliq_id]) does not. So why is this the case?
The find_by method matches on conditions. Using find_by, you can match on any attribute. For example, this would also work:
#cliq = Cliq.find_by(some_attribute: "foo")
So using find_by, you must specify the id attribute in order for the query to return the correct record. Your find_by query was actually running SQL that looked something like this:
SELECT `cliqs`.* FROM `cliqs` WHERE (2) LIMIT 1
That select statement will return the whole table, and the LIMIT 1 just grabs the first record.
As a bonus, the preferred rails way to assign #cliq based on an params[:cliq_id] would be using just find, which searches for the record using its primary key:
#cliq = Cliq.find(params[:cliq_id])