SQLBuilder\Universal\Syntax\Column::buildUnsignedClause PHP Метод

    public function buildUnsignedClause(BaseDriver $driver)
    {
        if ($driver instanceof SQLiteDriver || $driver instanceof PgSQLDriver) {
            // unsigned primary key is not supported in SQLiteDriver and PgSQLDriver
            return '';
        }
        if ($this->unsigned) {
            return ' UNSIGNED';
        }
        return '';
    }