alexcalaca

My profile: https://about.me/alexandrecalaca

1. Check your Rails version

rails -v

2. Open the Gemfile and replace the line "gem 'sqlite3" with gem 'pg', '~> 0.21'

gem 'pg', '~> 0.21'

alexcalaca

Remove files from the repository based on your .gitignore without deleting them from the local file system
git rm --cached `git ls-files -i -X .gitignore`

alexcalaca

This is block

\ It creates a line break

''' Test '''

Header

alexcalaca

My profile: https://about.me/alexandrecalaca

1. Check you RVM version

rvm version

You`re going to a message like this: rvm 1.29.2 (latest) by Michal Papis, Piotr Kuczynski, Wayne E. Seguin [https://rvm.io/]

2. Uninstall RVM gem

alexcalaca

My profile: https://about.me/alexandrecalaca

1. Update your system

sudo apt-get update

2. Install build-essential

sudo apt-get install -y build-essential

alexcalaca

Check my website: www.alexandrecalaca.com.br

Now, it's time to rock. Go to rails console.

rails console

Create one blog and see the slug created

alexcalaca

Check my website: www.alexandrecalaca.com.br

1. First of all, let's generate a migration that it is going to add a status attribute to the table.

rails generate migration add_post_status_to_blogs status:integer

2. Open the migration you have just created. Your code needs to be something like this:

def change
    add_column :blogs, :status, :integer, default: 0

alexcalaca

Visit my website: www.alexandrecalaca.com.br

In our example, there are2 models: Blog and Topic. Think about a single topic blog.

So, A blog can belong to only one topic. A topic has many different blogs.

Blog (N) X (1) topic The foreign key needs to be in the blog model.

alexcalaca

Lookup Active Record Query Interface http://guides.rubyonrails.org/active_record_querying.html

ActiveRecord::QueryMethods http://api.rubyonrails.org

Class methods http://api.rubyonrails.org/classes/ActiveRecord/Scoping/Named/ClassMethods.html

alexcalaca

PostgreSQL command line cheatsheet-ac.md

sudo -u postgres psql : Enter the console \password postgres : E

\du : List all users \l : List of databases \q : Disconnect