Compile the columns for the update statement

        :param values: The columns
        :type values: dict

        :return: The compiled columns
        :rtype: str

def _compile_update_columns(self, values):
        """
        Compile the columns for the update statement

        :param values: The columns
        :type values: dict

        :return: The compiled columns
        :rtype: str
        """
        columns = []

        for key, value in values.items():
            columns.append("%s = %s" % (self.wrap(key), self.parameter(value)))

        return ", ".join(columns)