如何基于选择选项更新表单上的字段

Question

I have a PHP form with the following select list;

<select id ="MatchCaptain" name="MatchCaptain" onchange="findTeleNo(this.value)"
                        <?php 
                            $MC = $_SESSION["MatchCapt"];
                            player_load($MC);
                        ?>
                        >
                </select>

I also have a text field ;

Telephone Number:&nbsp;</b> <?php echo $_SESSION["TeleNo"]; ?></p>

The PHP function called by the onchange command is ;

    function findTeleNo($MatchCaptain){
  $db_handle = mysqli_connect(DB_SERVER, DB_USER, DB_PASS );
    $database = "matchmanagementDB";
    $db_found = mysqli_select_db($db_handle, $database);
    if ($db_found) {
    $SQL = "SELECT * FROM `playerstb` ORDER BY `Surname` ASC, `FirstName` ASC";
    $result = mysqli_query($db_handle, $SQL); 
    $ufullName = split_name($MatchCaptain);
    while ( $db_field = mysqli_fetch_assoc($result) ) {
        $uName = $db_field['FirstName'];
        $uName = trim($uName);
        $Surname = $db_field['Surname'];
        $Surname = trim($Surname);
        $fullName = $uName." ".$Surname;
        if ($fullName == $ufullName )
        {
            $_SESSION["TeleNo"] = $db_field['TeleNo'];
            include "Match_sort.php";
            break;
        }
        }
}
}

What I am trying to do is when the Match Captains name is changed in the SELECT dropdown list then I want the FUNCTION findTeleNo() to run. Which should then reload the form with the telephone number of the New Match Captain. However, when I select a new Match Captain the onchange command is ignored. As a Septuagenarian, just learning this language, I need some help! Does onchange work in PHP? If not what should I use?

Answer 1

The onchange event is a javascript event, it cannot call your php function directly. You can create a javascript function that will be called when the selects value changes and then this can make an xhr(Ajax) request to a php file which will perform a database query and return what you need it to. You could then update the page with javascript.

Answer 2

PHP is a server side language, you need to use javascript for this.

this is example:

 function findTeleNo (value) { console.log(value); $.ajax({ url: 'findTeleNo.php', data: { c_name: value }, success: function (response) { $('#cname').text(response.cname); $('#teleno').text(response.teleno); } }); } 

 <script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script> <div> <select id ="MatchCaptain" name="MatchCaptain" onchange="findTeleNo(this.value)"> <option>choose one</option> <option value="A1">A1</option> <option value="B2">B2</option> <option value="C3">C3</option> </select> <div> <div> Captain Name is: <span id="cname">empty</span> <div> <div> TeleNo is: <span id="teleno">empty</span> <div> 

and in file findTeleNo.php you print json has cname and teleno.