Rails ::::::::::: Formulas and structures

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                  Rails :: ::::::::: Formulas and structures


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                          TYPE A  ::::::::::::::::::::::::::::::::  Add Columns and Remove Columns

                           Note:  After Every Command Run rake db:migrate or rails db:migrate

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Note  01    :: :::::::::       :: :::::::::      :: :::::::::         :: :::::::::        :: :::::::::       :: :::::::::      :: :::::::::


How to Add column in Rails:

$ rails generate migration AddPartNumberToProducts part_number:string


$ rails generate migration AddPartNumberToProducts part_number:string:index

Will Generate

class AddPartNumberToProducts < ActiveRecord::Migration[5.0]
  def change
    add_column :products, :part_number, :string
    add_index :products, :part_number
  end
end

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Note  02    :: :::::::::       :: :::::::::      :: :::::::::         :: :::::::::        :: :::::::::       :: :::::::::      :: :::::::::

How to Remove column in Rails:

$ rails generate migration RemovePartNumberFromProducts part_number:string

class RemovePartNumberFromProducts < ActiveRecord::Migration[5.0]
  def change
    remove_column :products, :part_number, :string
  end
end



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Note  03    :: :::::::::       :: :::::::::      :: :::::::::         :: :::::::::        :: :::::::::       :: :::::::::      :: :::::::::

How to Add  Multiple columns in Rails:

$ rails generate migration AddDetailsToProducts part_number:string price:decimal

class AddDetailsToProducts < ActiveRecord::Migration[5.0]
  def change
    add_column :products, :part_number, :string
    add_column :products, :price, :decimal
  end
end

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                                     TYPE B  ::::::::::::::::::::::::::::::::  Model Generators

                                                           Note:  Make Tables

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Note  01    :: :::::::::       :: :::::::::      :: :::::::::         :: :::::::::        :: :::::::::       :: :::::::::      :: :::::::::

How to Generate  Tables in Rails:

rails generate model Product name:string description:text


class CreateProducts < ActiveRecord::Migration[5.0]
  def change
    create_table :products do |t|
      t.string :name
      t.text :description
 
      t.timestamps
    end
  end
end



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