module Arel::Crud

def compile_update(
  values,
  key = nil,
  having_clause = nil,
  group_values_columns = []
)
  um = UpdateManager.new(source)
  um.set(values)
  um.take(limit)
  um.offset(offset)
  um.order(*orders)
  um.wheres = constraints
  um.key = key
  um.group(group_values_columns) unless group_values_columns.empty?
  um.having(having_clause) unless having_clause.nil?
  um
end