Compile an update statement into SQL

        :param query: A QueryBuilder instance
        :type query: QueryBuilder

        :param values: The update values
        :type values: dict

        :return: The compiled update
        :rtype: str

def compile_update(self, query, values):
        """
        Compile an update statement into SQL

        :param query: A QueryBuilder instance
        :type query: QueryBuilder

        :param values: The update values
        :type values: dict

        :return: The compiled update
        :rtype: str
        """
        table = self.wrap_table(query.from__)

        columns = self._compile_update_columns(values)

        from_ = self._compile_update_from(query)

        where = self._compile_update_wheres(query)

        return ("UPDATE %s SET %s%s %s" % (table, columns, from_, where)).strip()