带有bind_param（）的PHP UPDATE无法正常工作

Question

Good day, I'm not really familiar with PHP and i get this error when i try to execute my query.

Fatal error: Uncaught Error: Call to a member function bind_param() on boolean in C:\\xampp\\htdocs\\LoginWithMySQLi\\changenameaction.php:12 Stack trace: #0 {main} thrown in C:\\xampp\\htdocs\\LoginWithMySQLi\\changenameaction.php on line 12

here's my code:

session_start();

require_once 'dbconnect.php';

$stmt = $DBcon->prepare("UPDATE tbl_users SET fname = ?, lname = ?, WHERE user_id = ?");
    $stmt->bind_param('sss', $_POST['fname'], $_POST['lname'], $_SESSION['userSession']);
    $stmt->execute(); 
    $stmt->close();

$DBcon->close();

Do you know what i do wrong?

Thanks in Advance

Answer 1

The sql statement was failing the preparation stage so you should test that the statement is ok before proceeding with the other methods - the reason it failed was the extra comma before the WHERE clause

session_start();

require_once 'dbconnect.php';

$stmt = $DBcon->prepare("UPDATE tbl_users SET fname = ?, lname = ? WHERE user_id = ?");
if( $stmt && isset($_POST['fname'], $_POST['lname'], $_SESSION['userSession']) ){
    $stmt->bind_param('sss', $_POST['fname'], $_POST['lname'], $_SESSION['userSession'] );
    $stmt->execute(); 
    $stmt->close();
}
$DBcon->close();

Answer 2

你有一个逗号结尾，你的sql应该像这样

UPDATE tbl_users SET fname = ?, lname = ? WHERE user_id = ?