I'm having problem to write this code correctly - php

Question

I want to add this line
a href="r.php?id=<?php echo $row['id']; ?>" >Details>
which will display details of this id on another page.
but i don't know how to write this line correctly. can you help me please thank you.
$conn = new mysqli('localhost', 'root', '', 'dbmtc');
$perPage = 10;
$page = 0;
if (isset($_POST['page'])) {
$page = $_POST['page'];
} else {
$page=1;
};
$startFrom = ($page-1) * $perPage;
$sqlQuery = "SELECT fname, lname, dept, email
FROM staff ORDER BY fname ASC LIMIT $startFrom, $perPage";
//echo $sqlQuery;
$result = mysqli_query($conn, $sqlQuery);
$paginationHtml = '';
while ($row = mysqli_fetch_assoc($result)) {
$paginationHtml.='<tr>';
$paginationHtml.='<td>'.$row["fname"].' '.$row["lname"].'</td>';
$paginationHtml.='<td>'.$row["dept"].'</td>';
$paginationHtml.='<td>'.$row["email"].'</td>';
**this line should be here**
$paginationHtml.='</tr>';
}
$jsonData = array(
"html" => $paginationHtml,
);
echo json_encode($jsonData);
?>
This part is in index.php
<table class="table table-hover table-bordered">
<thead>
<tr>
<th>Name</th>
<th>Department</th>
<th>Email</th>
<th>Operations</th>
</tr>
</thead>
<tbody id="content">
</tbody>
</table>
This is the table
And when i insert
$paginationHtml .= '<td>Details</td>';
I got this I don't why, that why I said it's not good
enter image description here

Answer 1

First of all: You didn't select the ID in your sql query. Please add it in the selected fieds.
These are the possibilities to write this and you can choose one of them:
1- $paginationHtml .= '<td><a href="r.php?id='.$row['id'].'" >Details</a></td>';
2- $paginationHtml .= "<td><a href=\"r.php?id={$row['id']}\" >Details</a></td>";