Okay, so you have got the basic set up of your application, we need to create a basic database with users and a way for users to add content under posts. In order to do that you will have to create a migration.
First, let's start with running
rake -T and see all the options we have available to us.
rake console # Starts console rake db:create # Creates the database from DATABASE_URL or config/database.yml for the current RAILS_ENV (... rake db:create_migration # Create a migration (parameters: NAME, VERSION) rake db:drop # Drops the database from DATABASE_URL or config/database.yml for the current RAILS_ENV (us... rake db:environment:set # Set the environment value for the database rake db:fixtures:load # Loads fixtures into the current environment's database rake db:migrate # Migrate the database (options: VERSION=x, VERBOSE=false, SCOPE=blog) rake db:migrate:status # Display status of migrations rake db:prepare # Runs setup if database does not exist, or runs migrations if it does rake db:rollback # Rolls the schema back to the previous version (specify steps w/ STEP=n) rake db:schema:cache:clear # Clears a db/schema_cache.yml file rake db:schema:cache:dump # Creates a db/schema_cache.yml file rake db:schema:dump # Creates a db/schema.rb file that is portable against any DB supported by Active Record rake db:schema:load # Loads a schema.rb file into the database rake db:seed # Loads the seed data from db/seeds.rb rake db:seed:replant # Truncates tables of each database for current environment and loads the seeds rake db:setup # Creates the database, loads the schema, and initializes with the seed data (use db:reset ... rake db:structure:dump # Dumps the database structure to db/structure.sql rake db:structure:load # Recreates the databases from the structure.sql file rake db:version # Retrieves the current schema version number
As you can see if we run
rake db:create_migration with the correct parameters it will create a migration
So, lets create a users and posts migration by running the following code.
rake db:create_migration NAME=create_users and
rake db:create_migration NAME=create_posts
You will discover that this will create two files in your db/migrate directory. We will need to add the following code into the Users table.
class CreateUsers < ActiveRecord::Migration[6.0] def change create_table :users do |t| t.string :username end end end
Next, we will need to add the following code into the Posrs table.
class CreatePosts < ActiveRecord::Migration[6.0] def change create_table :posts do |t| t.string :title t.text :content t.integer :user_id end end end
You will also need to create two new files in models, one named user.rb and one named post.rb, which will inherit ActiveRecord::Base.
class Post < ActiveRecord::Base belongs_to :user end
class User < ActiveRecord::Base has_many :posts end
Lastly we will need to migrate these two tables by running,
If you run into errors while running
rake db:migrate please check you ActiveRecord::Migration version
If everything ran correctly, you should now be able to run
rake console or type
tux you will be able to modify your database including creating users and posts.
u = User.create(username: username= "John")
creates a user
p = Post.create(title: title= "first title", content: content="this is content")
creates a user
p.user = u
sets the user_id in post equal to the 'u' user
Should return the following:
=> #<Post:0x00007f8358b5eea0 id: 1, title: "first title", content: "this is content", user_id: 1>
Great! Now your database is all setup :) Play around in the
rake console and
tux to build up your database.