Logo Questions Linux Laravel Mysql Ubuntu Git Menu
HTML CSS JAVASCRIPT SQL PYTHON PHP BOOTSTRAP JAVA JQUERY R React Kotlin
 

What is :cascade in rails schema.rb and where did it come from?

Tags:

ruby-on-rails

After adding another migration and occasional decision to drop and migrate I checked my schema.rb and saw this

create_table "users", force: :cascade do |t|

I haven't committed this changes yet and on remote I have this

create_table "users", force: true do |t|

Now I have cascade in front of each table. What is cascade and where did it come from?

like image 433
kirqe Avatar asked Dec 29 '14 22:12

kirqe

People also ask

How is schema rb generated?

It is a Ruby representation of your database; schema. rb is created by inspecting the database and expressing its structure using Ruby.

What is schema rb in rails?

The schema. rb serves mainly two purposes: It documents the final current state of the database schema. Often, especially when you have more than a couple of migrations, it's hard to deduce the schema just from the migrations alone. With a present schema.

How do I roll back migration in Rails?

You must rollback the migration (for example with bin/rails db:rollback ), edit your migration, and then run bin/rails db:migrate to run the corrected version.

What are migrations in rails?

A Rails migration is a tool for changing an application's database schema. Instead of managing SQL scripts, you define database changes in a domain-specific language (DSL). The code is database-independent, so you can easily move your app to a new platform.

2 Answers

The docs explain what :cascade does:

:force - Set to :cascade to drop dependent objects as well. Defaults to false.

One reason you may be seeing this is a change in Rails 4.2 in SchemaDumper to use :cascade, release notes.

Release notes about change:

SchemaDumper uses force: :cascade on create_table. This makes it possible to reload a schema when foreign keys are in place.

like image 190
Andrew Hubbs Avatar answered Sep 30 '22 22:09

Andrew Hubbs

http://api.rubyonrails.org/classes/ActiveRecord/ConnectionAdapters/SchemaStatements.html#method-i-create_table

:force Set to true to drop the table before creating it. Set to :cascade to drop dependent objects as well. Defaults to false.

like image 29
Lane Avatar answered Sep 30 '22 23:09

Lane
Sign in to Comment

Related questions

Is there a CRUD generator utility in Java(any framework) like Scaffolding in Rails? [closed]
Cucumber / Capybara -- how to get the host and port of the current execution
Submit POST data from controller to another website in Rails
How to use all view and helper methods inside of Rails console for Rails 2.x and 3.x? [duplicate]
How do you structure i18n yaml files in Rails?
rails 3, how add a view that does not use same layout as rest of app?
How to emulate mouse hover with Capybara
How do I find the source file for a rake task?
How can I send mail with rails without a template?
Rails 4 + Devise: Password Reset is always giving a "Token is invalid" error on the production server, but works fine locally.
Rails server is still running in a new opened docker container
Rails: Get next / previous record
Ruby on Rails: the best way to compare two dates?
Access helpers from mailer?
Rails where() clause on model association?
Shared models between two Rails apps - what is the ideal solution for Workflow?
Ruby on Rails app on Google App Engine
Devise limit one session per user at a time
PG::ConnectionBad: fe_sendauth: no password supplied
Single table inheritance and where to use it in Rails

Donate For Us

If you love us? You can donate to us via Paypal or buy me a coffee so we can maintain and grow! Thank you!