Unable to create record via nested attributes Rails API - sql

Question

I'm currently trying to create an Order instance. There is an association of the model Order with Items. The association is as follows. Order has many Items. I try following the documentation https://api.rubyonrails.org/classes/ActiveRecord/NestedAttributes/ClassMethods.html
class Order < ApplicationRecord
has_many :items
accepts_nested_attributes_for :items
end
class OrdersController < ApplicationController
##
private
def order_params
params.require(:order).permit(:description,
items_attributes: [:id, :quantity])
end
end
From the following post, it shows that the id has to be pass in the params. Rails 5 Api create new object from json with nested resource
params = {order: {description: "this is a test"}, items_attributes: [{id: 3, quantity: 3, description: 'within order -> item'}]}
=> {:order=>{:description=>"this is a test"}, :items_attributes=>[{:id=>3, :quantity=>3, :description=>"within order -> item"}]}
[7] pry(main)> order_test = Order.create!(params[:order])
(0.4ms) BEGIN
Order Create (62.9ms) INSERT INTO "orders" ("description", "created_at", "updated_at") VALUES ($1, $2, $3) RETURNING "id" [["description", "this is a test"], ["created_at", "2019-05-30 23:31:39.409528"], ["updated_at", "2019-05-30 23:31:39.409528"]]
(4.6ms) COMMIT
=> #<Order:0x00007ff91556e4b8 id: 14, description: "this is a test", created_at: Thu, 30 May 2019 23:31:39 UTC +00:00, updated_at: Thu, 30 May 2019 23:31:39 UTC +00:00>
I create an order however when I check for the items it returns an empty array.
=> #<Order:0x00007ff9142da590 id: 14, description: "this is a test", created_at: Thu, 30 May 2019 23:31:39 UTC +00:00, updated_at: Thu, 30 May 2019 23:31:39 UTC +00:00>
[11] pry(main)> Order.last.items
Order Load (0.4ms) SELECT "orders".* FROM "orders" ORDER BY "orders"."id" DESC LIMIT $1 [["LIMIT", 1]]
Item Load (0.3ms) SELECT "items".* FROM "items" WHERE "items"."order_id" = $1 [["order_id", 14]]
=> []
Here is the table for items:
class CreateItems < ActiveRecord::Migration[5.2]
def change
create_table :items do |t|
t.references :order, foreign_key: true
t.integer :quantity
t.string :description
t.timestamps
end
end
end
What is wrong?

Answer 1

The mistake was in the order the parameters were being passed.
{:order=>{:id=>22, :description=>"this is a test", :items_attributes=>[{:order_id=>22, :quantity=>3, :description=>"within order -> item"}]}}
This solved it:
order = Order.create!(params[:order])
<Order:0x00007ff918039ee0 id: 22, description: "this is a test", created_at: Fri, 31 May 2019 01:39:23 UTC +00:00, updated_at: Fri, 31 May 2019 01:39:23 UTC +00:00>
[39] pry(main)> order.items
Item Load (114.8ms) SELECT "items".* FROM "items" WHERE "items"."order_id" = $1 [["order_id", 22]]
=> [#<Item:0x00007ff9180394b8
id: 4,
order_id: 22,
quantity: 3,
description: "within order -> item",
created_at: Fri, 31 May 2019 01:39:23 UTC +00:00,
updated_at: Fri, 31 May 2019 01:39:23 UTC +00:00>]