Columns

Column Types

• :primary_key
• :string: short-form text
• :text: long-form text
• :integer: whole numbers
• :float: double-precision floating-point numbers [3.141]
• :decimal: high-precision floating-point numbers [3.1415926535 8979323846 26433832]
• :boolean (true or false)
• :binary: (1 or 0)
• :date
• :time
• :datetime

Add a Column

bin/rails g migration AddKeywordsSizeToProduct keywords:string size:string

Migration for Adding a Column

class AddKeywordsSizeToProduct < ActiveRecord::Migration[6.1]
  def change
    add_column :products, :keywords, :string
    add_column :products, :size, :string
  end
end

Remove A Column

bin/rails g migration RemoveKeywordsFromProduct keywords

Migration for Removing a Column

class RemoveKeywordsFromProduct < ActiveRecord::Migration[6.1]
  def change
    remove_column :products, :keywords, :string
  end
end

Rename a Column

bin/rails g migration RenameProductPopularityToRanking

Migration for Renaming a Column

class RenameProductPopularityToRanking < ActiveRecord::Migration[6.1]
  def change
    rename_column :products, :popularity, :ranking
  end
end

Change a Column Type

bin/rails g migration ChangeProductPopularity

Migration for Changing Column Type

class ChangeProductPopularity < ActiveRecord::Migration[6.1]
  def change
      change_column :products, :ranking, :decimal, precision: 10, scale: 2
  end
end