instance method
revert
Ruby on Rails 4.1.16
Since v3.2.22.5Signature
revert(*migration_classes)Reverses the migration commands for the given block and the given migrations.
The following migration will remove the table ‘horses’ and create the table ‘apples’ on the way up, and the reverse on the way down.
class FixTLMigration < ActiveRecord::Migration
def change
revert do
create_table(:horses) do |t|
t.text :content
t.datetime :remind_at
end
end
create_table(:apples) do |t|
t.string :variety
end
end
end
Or equivalently, if TenderloveMigration is defined as in the documentation for Migration:
require_relative '2012121212_tenderlove_migration'
class FixupTLMigration < ActiveRecord::Migration
def change
revert TenderloveMigration
create_table(:apples) do |t|
t.string :variety
end
end
end
This command can be nested.
Parameters
-
migration_classesrest
Source
# File activerecord/lib/active_record/migration.rb, line 480
def revert(*migration_classes)
run(*migration_classes.reverse, revert: true) unless migration_classes.empty?
if block_given?
if @connection.respond_to? :revert
@connection.revert { yield }
else
recorder = CommandRecorder.new(@connection)
@connection = recorder
suppress_messages do
@connection.revert { yield }
end
@connection = recorder.delegate
recorder.commands.each do |cmd, args, block|
send(cmd, *args, &block)
end
end
end
end
Defined in activerecord/lib/active_record/migration.rb line 480
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Defined in ActiveRecord::Migration