pyk · August 2, 2021 09:20 · Jan 23, 2014 · Jan 23, 2014 · Jan 22, 2014 · Jan 22, 2014
diff --git a/active-record-migrate-expert.md → active-record-migration-expert.md b/active-record-migrate-expert.md → active-record-migration-expert.md
diff --git a/data-modeling.md → active-record-migrate-expert.md b/data-modeling.md → active-record-migrate-expert.md
@@ -1,4 +1,4 @@
-become database modeling expert (Rails 4.0.2)
+become active record migration expert (Rails 4.0.2)
 ============================================
 
 workflow:

diff --git a/data-modeling.md b/data-modeling.md
@@ -149,7 +149,7 @@ end
  - when you migrate the wrong table you can rollback using `rake db:rollback`
  - update your table with create new migration (add/remove). 
 
-> I think, updating your table with edit your previous migration is not best practice. my experience updating table with edit previous migration and then execute `rake db:migrate` is doesn't work. 
+> I think, updating your table by editing your previous migration is not best practice. my experience updating table by editing my previous migration and then execute `rake db:migrate` is doesn't work. 
 
 ## more resource
 [Active Record Migrations][ar]

diff --git a/data-modeling.md b/data-modeling.md
@@ -22,13 +22,13 @@ $ rails g model NameOfModel
 2. define field in format `t.field_type :field_name`
 ``` ruby
 class CreateNameOfModels < ActiveRecord::Migration
-  def change
-    create_table :name_of_models do |t|
-      t.string :name
-      t.integer :age
-      t.timestamps
+    def change
+        create_table :name_of_models do |t|
+            t.string :name
+            t.integer :age
+            t.timestamps
+        end
     end
-  end
 end
 ```
 
@@ -82,18 +82,18 @@ $ rails g migration AddDetailsToNameOfModels first_name last_name phone_number a
 2. open up `db/migrate/YYYYMMDDHHMMSS_add_details_to_name_of_models.rb`
 ``` ruby
 class AddDetailsToNameOfModels < ActiveRecord::Migration
-  def change
-    add_column :name_of_models, :first_name, :string
-    add_column :name_of_models, :last_name, :string
-    add_column :name_of_models, :phone_number, :string
-    add_reference :name_of_models, :anothertables, index: true
-  end
+    def change
+        add_column :name_of_models, :first_name, :string
+        add_column :name_of_models, :last_name, :string
+        add_column :name_of_models, :phone_number, :string
+        add_reference :name_of_models, :anothertables, index: true
+    end
 end
 ```
 make sure you have exactly column name and type before migrating
 
 3. run `rake db:migrate`
-```
+``` shell
 $ rake db:migrate
 ==  AddDetailsToNameOfModels: migrating =======================================
 -- add_column(:name_of_models, :first_name, :string)
@@ -110,37 +110,37 @@ $ rake db:migrate
 #### remove column
 
 1. run rails generator with `Remove[column]From[model]` format followed by column you want to remove
-```
+``` shell
 $ rails g migration RemovePhoneNumberFromNameOfModels phone_number:string
       invoke  active_record
       create    db/migrate/YYYYMMDDHHMMSS_remove_phone_number_from_name_of_models.rb
 ```
 
 2. open `db/migrate/YYYYMMDDHHMMSS_remove_phone_number_from_name_of_models` to make sure.
-```
+``` ruby
 class RemovePhoneNumberFromNameOfModels < ActiveRecord::Migration
-  def change
-    remove_column :name_of_models, :phone_number, :string
-  end
+    def change
+        remove_column :name_of_models, :phone_number, :string
+    end
 end
 ```
 
 #### remove multiple columns at once
 1.  run rails generator with `RemoveDetailsFrom[model]` format followed by column you want to remove
-```
+``` shell
 › rails g migration RemoveDetailsFromNameOfModels first_name last_name anothertables:belongs_to
       invoke  active_record
       create    db/migrate/YYYYMMDDHHMMSS_remove_details_from_name_of_models.rb
 ```
 
 2. open `db/migrate/YYYYMMDDHHMMSS_remove_details_from_name_of_models.rb`
-```
+``` ruby
 class RemoveDetailsFromNameOfModels < ActiveRecord::Migration
-  def change
-    remove_column :name_of_models, :first_name, :string
-    remove_column :name_of_models, :last_name, :string
-    remove_reference :name_of_models, :anothertables, index: true
-  end
+    def change
+        remove_column :name_of_models, :first_name, :string
+        remove_column :name_of_models, :last_name, :string
+        remove_reference :name_of_models, :anothertables, index: true
+    end
 end
 ```
 3. if you are sure with what you do, then run `rake db:migrate`. it will remove all column or reference that you define on `db/migrate/YYYYMMDDHHMMSS_remove_details_from_name_of_models.rb`

diff --git a/data-modeling.md b/data-modeling.md
@@ -149,7 +149,7 @@ end
  - when you migrate the wrong table you can rollback using `rake db:rollback`
  - update your table with create new migration (add/remove). 
 
-> I think, updating your table with edit your previous migration is not best practice. my experience updating table with edit previous migration and run `rake db:migrate` it's doesn't work. 
+> I think, updating your table with edit your previous migration is not best practice. my experience updating table with edit previous migration and then execute `rake db:migrate` is doesn't work. 
 
 ## more resource
 [Active Record Migrations][ar]

diff --git a/data-modeling.md b/data-modeling.md
@@ -0,0 +1,157 @@
+become database modeling expert (Rails 4.0.2)
+============================================
+
+workflow:
+
+### create model
+``` shell
+$ rails g model NameOfModel
+    invoke  active_record
+    create    db/migrate/YYYYMMDDHHMMSS_create_name_of_models.rb
+    create    app/models/name_of_model.rb
+    invoke    test_unit
+    create      test/models/name_of_model_test.rb
+    create      test/fixtures/name_of_models.yml
+
+```
+
+### create `name_of_models` table and define some columns
+
+1. open `db/migrate/YYYYMMDDHHMMSS_create_name_of_models.rb`
+
+2. define field in format `t.field_type :field_name`
+``` ruby
+class CreateNameOfModels < ActiveRecord::Migration
+  def change
+    create_table :name_of_models do |t|
+      t.string :name
+      t.integer :age
+      t.timestamps
+    end
+  end
+end
+```
+
+3. run `rake db:migrate`
+``` shell
+$ rake db:migrate
+==  CreateNameOfModels: migrating =============================================
+-- create_table(:name_of_models)
+   -> 0.0085s
+==  CreateNameOfModels: migrated (0.0087s) ====================================
+```
+this will create `name_of_models` table with `name` and `age` columns.
+
+### updating `name_of_models` table
+
+#### add another column
+1. run rails generator with `Add[column]To[model]` format followed by column
+``` shell
+$ rails g migration AddBioToNameOfModels bio:text
+    invoke  active_record
+    create    db/migrate/YYYYMMDDHHMMSS_add_bio_to_name_of_models.rb
+```
+
+2. open `db/migrate/YYYYMMDDHHMMSS_add_bio_to_name_of_columns.rb`
+``` ruby
+class AddBioToNameOfModels < ActiveRecord::Migration
+  def change
+    add_column :name_of_models, :bio, :text
+  end
+end
+```
+
+3. run `rake db:migrate`
+``` shell
+› rake db:migrate
+==  AddBioToNameOfModels: migrating ===========================================
+-- add_column(:name_of_models, :bio, :text)
+   -> 0.0067s
+==  AddBioToNameOfModels: migrated (0.0069s) ==================================
+```
+
+#### add multiple columns at once
+
+1. run rails generator with `AddDetailsTo[model]` format followed by list of columns
+``` shell
+$ rails g migration AddDetailsToNameOfModels first_name last_name phone_number anothertables:belongs_to
+    invoke  active_record
+    create    db/migrate/YYYYMMDDHHMMSS_add_details_to_name_of_models.rb
+```
+
+2. open up `db/migrate/YYYYMMDDHHMMSS_add_details_to_name_of_models.rb`
+``` ruby
+class AddDetailsToNameOfModels < ActiveRecord::Migration
+  def change
+    add_column :name_of_models, :first_name, :string
+    add_column :name_of_models, :last_name, :string
+    add_column :name_of_models, :phone_number, :string
+    add_reference :name_of_models, :anothertables, index: true
+  end
+end
+```
+make sure you have exactly column name and type before migrating
+
+3. run `rake db:migrate`
+```
+$ rake db:migrate
+==  AddDetailsToNameOfModels: migrating =======================================
+-- add_column(:name_of_models, :first_name, :string)
+   -> 0.0068s
+-- add_column(:name_of_models, :last_name, :string)
+   -> 0.0009s
+-- add_column(:name_of_models, :phone_number, :string)
+   -> 0.0008s
+-- add_reference(:name_of_models, :anothertables, {:index=>true})
+   -> 0.0016s
+==  AddDetailsToNameOfModels: migrated (0.0108s) ==============================
+```
+
+#### remove column
+
+1. run rails generator with `Remove[column]From[model]` format followed by column you want to remove
+```
+$ rails g migration RemovePhoneNumberFromNameOfModels phone_number:string
+      invoke  active_record
+      create    db/migrate/YYYYMMDDHHMMSS_remove_phone_number_from_name_of_models.rb
+```
+
+2. open `db/migrate/YYYYMMDDHHMMSS_remove_phone_number_from_name_of_models` to make sure.
+```
+class RemovePhoneNumberFromNameOfModels < ActiveRecord::Migration
+  def change
+    remove_column :name_of_models, :phone_number, :string
+  end
+end
+```
+
+#### remove multiple columns at once
+1.  run rails generator with `RemoveDetailsFrom[model]` format followed by column you want to remove
+```
+› rails g migration RemoveDetailsFromNameOfModels first_name last_name anothertables:belongs_to
+      invoke  active_record
+      create    db/migrate/YYYYMMDDHHMMSS_remove_details_from_name_of_models.rb
+```
+
+2. open `db/migrate/YYYYMMDDHHMMSS_remove_details_from_name_of_models.rb`
+```
+class RemoveDetailsFromNameOfModels < ActiveRecord::Migration
+  def change
+    remove_column :name_of_models, :first_name, :string
+    remove_column :name_of_models, :last_name, :string
+    remove_reference :name_of_models, :anothertables, index: true
+  end
+end
+```
+3. if you are sure with what you do, then run `rake db:migrate`. it will remove all column or reference that you define on `db/migrate/YYYYMMDDHHMMSS_remove_details_from_name_of_models.rb`
+
+### tips
+ - when you migrate the wrong table you can rollback using `rake db:rollback`
+ - update your table with create new migration (add/remove). 
+
+> I think, updating your table with edit your previous migration is not best practice. my experience updating table with edit previous migration and run `rake db:migrate` it's doesn't work. 
+
+## more resource
+[Active Record Migrations][ar]
+
+[ar]: http://guides.rubyonrails.org/migrations.html