Using URL to highlight a table row

[Chelle22]

I have a table in a database and my question is how can I create it ... that when I type .../array.php?id=1 into the url, it will highlight that row. If I put id=2 in, then it will highlight row 2

<?php
function connect(){
  // Make a MySQL Connection
  $link = mysqli_connect("localhost", "root", "", "school") or die(mysqli_error());
  return $link;
}
 
if ($_GET)
{
  if(isset($_GET["id"])) $id = $_GET["id"]; 
}
 
 
// select query 
$query = "SELECT * FROM graden" ;
 
if (isset($id)) { $query.= " WHERE id = $id "; }
 
$result = mysqli_query(connect(),$query);   
 
// table making
$table = "<table border='1'>";
$table .= "<tr>
             <th> ID </th>
             <th>Graden Celcius</th> 
             <th>Aanduiding</th>
             <th>Image</th> 
        </tr>";
 
// keeps getting the next row until there are no more to get
while($row = mysqli_fetch_assoc( $result )) {
    // Print out the contents of each row into a table
    foreach ($row as $key => $value) {
        if ($key == "Image") {
            $table .="<td><img src='$value' /></td>"; 
        } elseif ($key == "temp") {
            $table .="<td><a href='array.php?id=$value'>$value</a></td>"; 
        } else {
            $table .="<td>$value</td>";         
        }
 
    }
    $table .= "</tr>";
}
 
$table .="</table>";
 
echo $table;
?>

[Claus Mygind]

First of all it looks like from your code you are only returning one record and not the entire content of the data base table, because of the "where" clause in your sql query

If that is the case why would you need to highlight it?

But if you were returning multiple records and want to hightlight only the requested line.
1) eliminate the where
2) make a test for the id when scrolling out the lines for the table you want to display.

if (id == paramId)
{
  <td style="background-color: blue;">
}else{
  <td>
}