discourse/spec/fixtures/migrate/remove_column/20990309014014_remove_column.rb

class RemoveColumn < ActiveRecord::Migration[5.1]
  def up
    remove_column :users, :username
  end

  def down
    raise "not tested"
  end
end
FEATURE: protect against accidental column or table drops Often we need to amend our schema, it is tempting to use drop_table, rename_column and drop_column to amned schema trouble though is that existing code that is running in production can depend on the existance of previous schema leading to application breaking until new code base is deployed. The commit enforces new rules to ensure we can never drop tables or columns in migrations and instead use Migration::ColumnDropper and Migration::TableDropper to defer drop the db objects 2018-03-20 15:20:50 +08:00			`class RemoveColumn < ActiveRecord::Migration[5.1]`
			`def up`
			`remove_column :users, :username`
			`end`

			`def down`
			`raise "not tested"`
			`end`
			`end`