module Arel::Crud

def compile_delete(key = nil, having_clause = nil, group_values_columns = [])
  dm = DeleteManager.new(source)
  dm.take(limit)
  dm.offset(offset)
  dm.order(*orders)
  dm.wheres = constraints
  dm.key = key
  dm.group(group_values_columns) unless group_values_columns.empty?
  dm.having(having_clause) unless having_clause.nil?
  dm
end