class Sequel::MigrationDSL

Internal class used by the Sequel.migration DSL, part of the migration extension.

def self.create(&block) 

def self.create(&block)
  new(&block).migration
end

def change(&block)

in all cases, but it should work for most common cases.
There are no guarantees that this will work perfectly

the block.
to create a +down+ block that will reverse the changes made by
the same block with +up+, but it also calls the block and attempts
Creates a reversible migration. This is the same as creating 
def change(&block)
  migration.up = block
  migration.down = MigrationReverser.new.reverse(&block)
end

def down(&block)

Defines the migration's down action. 
def down(&block)
  migration.down = block
end

def initialize(&block)

Create a new migration class, and instance_eval the block. 
def initialize(&block)
  @migration = SimpleMigration.new
  Migration.descendants << migration
  instance_eval(&block)
end

def no_transaction

Disable the use of transactions for the related migration 
def no_transaction
  migration.use_transactions = false
end

def up(&block)

Defines the migration's up action. 
def up(&block)
  migration.up = block
end