将下拉列表值保存到php会话

Question

I have created a drop down list that is populated by data from mysql db, im trying to save the selected value in a session variable but im not sure how to write this (where the *** are)? And does it need to be posted to server side eve though its all in php?

    <?php
$servername1 = "localhost";
$username1 = "root";
$password1 = "";
$dbname1 = "gpdb1";
$conn1 = new mysqli($servername1, $username1, $password1, $dbname1);
if ($conn1->connect_error) {
die("connection failed: " . $conn1->connect_error);
}
$sql2 = "SELECT DoctorID, Title, Surname FROM doctors";
$result2 = $conn1->query($sql2);
echo "<select name='doctor' value=''><option>Select a Doctor</option>";
if ($result2->num_rows > 0) {
foreach($result2 as $row2) 
{echo "<option value=".$row2['DoctorID'].">".$row2['Title']."     ".$row2['Surname']."</option>"; 
}
}echo "</select>";
$_SESSION['selected']=***;
if (isset($_SESSION['selected'])){
echo $SESSION['selected'];}
?>

Thanks :)

Answer 1

First, I advise you to indent your code, for better readability !

The HTML attribute "value" in your tag isn't useful, you can remove it.

And then, it is not useful to control your session field with isset() since you're setting it just above.

I think that you just need to control if the given value in the post field is correct.

The line you are looking for is :

$_SESSION['selected'] = $_POST['doctor'];