compile_delete

# File activerecord/lib/arel/crud.rb, line 32
    def compile_delete(key = nil)
      dm = DeleteManager.new(source)
      dm.take(limit)
      dm.offset(offset)
      dm.order(*orders)
      dm.wheres = constraints
      dm.comment(comment)
      dm.key = key
      dm.ast.groups = @ctx.groups
      @ctx.havings.each { |h| dm.having(h) }
      dm
    end