php查询错误插入[重复]

Question

This question already has an answer here:

• “Notice: Undefined variable”, “Notice: Undefined index”, and “Notice: Undefined offset” using PHP 28 answers

<?php
$username = "...";
$password = "...";
$database = "...";



switch($_POST['function'])
{
    case 'register':
        $db_handle = new mysqli('localhost',$username,$password,$database);
        $sql = "SELECT * FROM `GameSaves` WHERE `Username` = '$un' and `Password` = '$pw'";

        if (!$db_handle->connect_error)
        {
            $r = $db_handle->query($sql);
            $count= $r->num_rows;

            $un = $_POST['username'];
            $pw = $_POST['password'];
            $data = '0';

            if ($count == 1)
                echo "fail";
            else
            {
                $sql = "INSERT INTO `GameSaves` (Username,Password,SaveData) VALUES ('test1','test2','0')";
                $res = $dbl_handle->query($sql);
                echo "succes";
            }
        }
        mysqli_close($db_handle);
    break;

    case 'login':
        $un = $_POST['username'];
        $pw = $_POST['password'];

        $db_handle = new mysqli('localhost',$username,$password,$database);
        $sql = "SELECT * FROM `GameSaves` WHERE `Username` = '$un' and `Password` = '$pw'";

        if (!$db_handle->connect_error)
        {
            $r = $db_handle->query($sql);
            $count= $r->num_rows;

            if ($count == 1)
                echo "succes";
            else
                echo "fail";
        }
        mysqli_close($db_handle);
    break;

    case 'getdata':
        $un = $_POST['username'];
        $sql = "SELECT * FROM `GameSaves` WHERE `Username` = '$un'";
        $db_handle = new mysqli('localhost',$username,$password,$database);

        if (!$db_handle -> connect_error)
        {
            $retval = $db_handle->query($sql);

            while ($row = $retval->fetch_assoc())
            {
                echo "{$row['SaveData']}";
            }
            mysqli_close($db_handle);
        }
    break;

    case 'savedata':
        $un = $_POST['username'];
        $db_handle = new mysqli('localhost',$username,$password,$database);

        if (!$db_handle -> connect_error)
        {   
            $data = $_POST['data'];
            $retval = $db_handle->query("UPDATE `GameSaves` SET `SaveData` = '$data' WHERE `Username` = '$un'");
            mysqli_close($db_handle);
        }
    break;
}
?>

This is my class.

I get the error: call to a member function query() on a non-object on line 28. I am clueless what to change on the $sql at register case. I looked everywhere on the internet but I can't find a solution to my problem.

</div>

Answer 1

There is a typo in your code.

change

$dbl_handle->query($sql);

to

$db_handle->query($sql);