mert

mert

Agile Web Development with Rails 7: page 120

Hello everyone,

I am relatively new to rails. I am reading AWDWR 7.

I am at page 120, I have some questions and having some problems.

Questions:

  • In line_item model we create a relationship to product and cart models. Do we need a n x m relationship between product and cart models? Because of that we create the line_item model?

  • Also inside the product and cart models we have has_many :line_items. Where is these relationships inside our schema.rb? I don’t see any sql relationship? If we don’t have a sql relationship is it good way to create relationships in ruby?

Need help code debugging:

  • I think I am having some problem. inside the line_items_controller.rb in the create method at @line_item = @cart.line_items.build(product: product) it gives me error. Saying : ActiveModel::MissingAttributeError in LineItemsController#create
    can’t write unknown attribute product_id. Any helps solving this problem

Thank you @rubys for this book!

Have a great day!

Mert

Marked As Solved

rubys

rubys

Author of Agile Web Development With Rails

It looks like your line_items are missing both a product and a cart. Those should have been added when you generated your scaffold in Iteration D2.

You can add them now with the following:

bin/rails generate migration AddProductAndCartToLineItems product:references cart:belongs_to

Where Next?

Popular Pragmatic Bookshelf topics Top

jimschubert
In Chapter 3, the source for index introduces Config on page 31, followed by more code including tests; Config isn’t introduced until pag...
New
GilWright
Working through the steps (checking that the Info,plist matches exactly), run the demo game and what appears is grey but does not fill th...
New
jamis
The following is cross-posted from the original Ray Tracer Challenge forum, from a post by garfieldnate. I’m cross-posting it so that the...
New
Alexandr
Hi everyone! There is an error on the page 71 in the book “Programming machine learning from coding to depp learning” P. Perrotta. You c...
New
alanq
This isn’t directly about the book contents so maybe not the right forum…but in some of the code apps (e.g. turbo/06) it sends a TURBO_ST...
New
jskubick
I’m under the impression that when the reader gets to page 136 (“View Data with the Database Inspector”), the code SHOULD be able to buil...
New
jskubick
I found an issue in Chapter 7 regarding android:backgroundTint vs app:backgroundTint. How to replicate: load chapter-7 from zipfile i...
New
digitalbias
Title: Build a Weather Station with Elixir and Nerves: Problem connecting to Postgres with Grafana on (page 64) If you follow the defau...
New
ggerico
I got this error when executing the plot files on macOS Ventura 13.0.1 with Python 3.10.8 and matplotlib 3.6.1: programming_ML/code/03_...
New
davetron5000
Hello faithful readers! If you have tried to follow along in the book, you are asked to start up the dev environment via dx/build and ar...
New

Other popular topics Top

New
AstonJ
Curious to know which languages and frameworks you’re all thinking about learning next :upside_down_face: Perhaps if there’s enough peop...
New
Rainer
My first contact with Erlang was about 2 years ago when I used RabbitMQ, which is written in Erlang, for my job. This made me curious and...
New
PragmaticBookshelf
From finance to artificial intelligence, genetic algorithms are a powerful tool with a wide array of applications. But you don't need an ...
New
PragmaticBookshelf
Rust is an exciting new programming language combining the power of C with memory safety, fearless concurrency, and productivity boosters...
New
New
PragmaticBookshelf
Author Spotlight Mike Riley @mriley This month, we turn the spotlight on Mike Riley, author of Portable Python Projects. Mike’s book ...
New
PragmaticBookshelf
Get the comprehensive, insider information you need for Rails 8 with the new edition of this award-winning classic. Sam Ruby @rubys ...
New
AstonJ
Curious what kind of results others are getting, I think actually prefer the 7B model to the 32B model, not only is it faster but the qua...
New
Fl4m3Ph03n1x
Background Lately I am in a quest to find a good quality TTS ai generation tool to run locally in order to create audio for some videos I...
New

Latest in Agile Web Development with Rails 7

Agile Web Development with Rails 7 Portal

Sub Categories: