Working with migrations and VERSIONs

Author: kinseyost

README.md

@@ -73,7 +73,7 @@ rails server
 ```
 Or in cloud9
 ```
-rails s -b $IP -p $PORT -e c9development
+rails s -b $IP -p $PORT -e c9
 ```
 
 ## Navigating this tutorial
@@ -150,7 +150,7 @@ rake db:schema:dump RAILS_ENV=production'
 ```
 or for cloud9, 
 ```
-rake db:schema:dump RAILS_ENV=c9development'
+rake db:schema:dump RAILS_ENV=c9'
 ```
 
 ## Migrations
@@ -167,7 +167,31 @@ rails generate model ModelName
 ```
 
 #### Running our migrations
+*For any of the `rake` commands in cloud9, append `RAILS_ENV=c9`.*
+Rake will create the tables we have specified in our migration files, and add entries for each of the migrations keyed by their timestamp.
 ```
-rake db:migrate RAILS_ENV=c9development
+rake db:migrate
 ```
 
+View the migrations in the database under the schema_migrations table.
+``` sql
+SELECT * FROM schema_migrations;
+```
+
+#### Taking down migrations
+This will take down all of your migrations.
+```
+rake db:migrate VERSION=0
+```
+#### Get the status of the migrations
+To see if migrations are up or down
+```
+rake db:migrate:status 
+```
+
+#### VERSIONs
+You can go through the migrations sequentially by using VERSION=<timestamp> of whatever version.
+So if you only wanted to run the Create users migration, you'd enter
+```
+rake db:migrate VERSION=20160917170621
+```

config/database.yml

@@ -21,7 +21,7 @@ development:
   <<: *default
   database: simple_cms_development
 
-c9development:
+c9:
   <<: *default
   adapter: mysql2
   encoding: utf8

config/secrets.yml

@@ -13,7 +13,7 @@
 development:
   secret_key_base: 418f74ba6ff80231c456be58a0b9174ce2c732466ec4bc9cd29d70f7f170114067f909c3d18aef1890ce720c7d29e5dc40c1cb58d946156e5aef083be7aade5c
 
-c9development:
+c9:
   secret_key_base: 418f74ba6ff80231c456be58a0b9174ce2c732466ec4bc9cd29d70f7f170114067f909c3d18aef1890ce720c7d29e5dc40c1cb58d946156e5aef083be7aade5c
 
 

db/migrate/20160917190210_second_migration.rb

@@ -0,0 +1,4 @@
+class SecondMigration < ActiveRecord::Migration[5.0]
+  def change
+  end
+end

db/schema.rb

@@ -10,7 +10,7 @@
 #
 # It's strongly recommended that you check this file into your version control system.
 
-ActiveRecord::Schema.define(version: 20160917170621) do
+ActiveRecord::Schema.define(version: 20160917190210) do
 
   create_table "users", force: :cascade, options: "ENGINE=InnoDB DEFAULT CHARSET=latin1" do |t|
     t.string   "first_name", limit: 25