使用PHP将html输出中的席位组织成表行

I'm putting together something that's mean to allow for a user to book seats for a cinema showing. The row and seat numbers for every showing are stored in the database. I'm currently extracting them in the following method so that users can click on a seat button to select that seat for their booking:

echo "<form>";
echo "<table>";
while($row = mysqli_fetch_assoc($result)){
    $rownum = $row['row'];
    $seat = $row['seat'];

    echo "<tr><td><button type=\"submit\" name=\"seatsel\" value=\"$rownum$seat\">$rownum$seat</button></td></tr>";
}
echo "</table>";

Right now this just outputs html showing all of the buttons as a single row in the table. I'd like the output to show seating across a single table row for every one of the table rows in the cinema screen. I'm not sure how to do this exactly given that each row is of differing lengths. E.g row A has twelve seats while row C has eight.

What would be the best way of accomplishing this?

You could easily update your code so that you will get a new table row every time the mysql row has another value. One thing to note is that you might want to add (depending on whether you're already sorting your results) the following ORDER BY row,seat.

echo "<form>";
echo "<table>";
echo "<tr>";
while($row = mysqli_fetch_assoc($result)){
    if (!isset($oldrownumber)) $oldrownumber = $row['row'];
    else if ($oldrownumber != $row['row']) {
        echo "</tr><tr>";
        $oldrownumber = $row['row'];
    }
    $rownum = $row['row'];
    $seat = $row['seat'];

    echo "<td><button type=\"submit\" name=\"seatsel\" value=\"$rownum$seat\">$rownum$seat</button></td>";
}
echo "</tr>";
echo "</table>";