Remove an existing column from a table

To remove existing column name from users table, run the command:

rails generate migration RemoveNameFromUsers name:string

This will generate the following migration:

class RemoveNameFromUsers < ActiveRecord::Migration[5.0]
  def change
    remove_column :users, :name, :string
  end
end

When the migration name is of the form RemoveXXXFromYYY followed by list of columns with data types then the generated migration will contain the appropriate remove_column statements.

While it’s not required to specify the data type (e.g. :string) as a parameter to remove_column, it is highly recommended. If the data type is not specified, then the migration will not be reversible.