How to combine two MySQL columns to one column?

I want to convert this MySQL table:

title1 | title2 |type  
-------+--------+----
qwe1   | qwe2   | 3  
asd1   | asd2   | 7

to this table in PHP

title | type  
------+-----
asd1  | 7  
asd2  | 7  
qwe1  | 3  
qwe1  | 3

But I don't know how to order the PHP table by the first column correctly.

(This is the code I am currently using)

$sql = "SELECT * FROM table ORDER BY title1, title2";   
$pager = new PS_Pagination( $dbh, $sql, 3, 4, null );//pagination class
$rs = $pager->paginate(); 

while ($row = $rs->fetch(PDO::FETCH_ASSOC)){
    echo "<tr>";
    echo "<td>{$row['title1']}</td>";
    echo "<td>{$row['type']}</td>";
    echo "</tr>";

    echo "<tr>";
    echo "<td>{$row['title2']}</td>";
    echo "<td>{$row['type']}</td>";
    echo "</tr>";
}       

echo "</table>";