Creating a dynamic table with rowspan PHP - php

Question

How to create a table with data retrieved from MySQL with PHP
-------------------------
| albumID | trackID |
-------------------------
| | 1990 |
- 1 -------------
| | 1991 |
-------------------------
| | 1992 |
- -------------
| 2 | 1993 |
- -------------
| | 1994 |
-------------------------
I can generate a table from the database, but the result will be only like each result in one row
$query = "SELECT albumID, trackID
FROM songs";
$result = mysqli_query($db, $query);
echo "<table>";
echo "<tr>\n";
echo "<th>albumID</th>\n";
echo "<th>trackID</th>\n";
echo "</tr>\n";
while ($data = mysqli_fetch_array($result)) {
echo "<tr>\n";
echo "<td>$data[0]</td>\n";
echo "<td>$data[1]</td>\n";
echo "</tr>\n";
}
echo "</table>\n";
Any help given is really appreciated!

Answer 1

You can do this by using a variable to keep track of the current album and only output the album once as shown below.
$current_album = ''; # initialize tracking var
while ($data = mysqli_fetch_array($result)) {
echo "<tr>\n";
if ($current_album != $data[0]) {
echo "<td>$data[0]</td>\n";
$current_album = $data[0];
} else {
echo "<td> </td>\n"; # insert empty cell
}
echo "<td>$data[1]</td>\n";
echo "</tr>\n";
}
This will have the album ID appearing in the first row for the album. If you want it to be vertically centered you can use rowspan on the td element, but in order to know how many rows each album has you will either need to update your sql query to return that or you can process the results into a multidimensional array and then loop through that to generate the output.

Answer 2

Maybe not the most elegant solution, but should do the trick.
$query = "select albumID as album, group_concat(trackID) as tracks from songs group by albumID";
$result = mysqli_query($db, $query);
echo "<table>";
echo "<tr>\n";
echo "<th>albumID</th>\n";
echo "<th>trackID</th>\n";
echo "</tr>\n";
while ($data = mysqli_fetch_array($result)) {
$tracks = explode(",", $data[1]);
echo "<tr>\n";
echo "<td rowspan=\"".count($tracks)."\">$data[0]</td>\n";
foreach ($tracks as $key => $value) {
echo "<td>$value</td>\n"
}
echo "</tr>\n";
}
echo "</table>\n";

Answer 3

Edit your query to return the numbers of tracks of the album and use that number to create a rowspan only on the first track row. I wrote a little example but I havn't tried if it works.
$query = "SELECT s.albumID, s.trackID,
( SELECT COUNT(*)
FROM songs s2
WHERE s2.albumID = s.albumID )
FROM songs s";
$result = mysqli_query($db, $query);
echo "<table>";
echo "<tr>\n";
echo "<th>albumID</th>\n";
echo "<th>trackID</th>\n";
echo "</tr>\n";
$tmpAlbum = '';
while ($data = mysqli_fetch_array($result)) {
echo "<tr>\n";
echo "<td";
if($data[2] == 1){
echo "<td>$data[0]</td>\n";
}else{
if($data[0] != $tmpAlbum){
echo "<td rowspan=\"".$data[2]."\">$data[0]</td>\n";
}
}
$tmpAlbum = $data[0];
echo "<td>$data[1]</td>\n";
echo "</tr>\n";
}
echo "</table>\n";