Question

在第17行上，我收到此错误，并且不确定该如何纠正。似乎与mysqli调用查询函数有关。

if (isset($_POST['un'])) {
    $user = sanitizeString($_POST['un']);
    $pass = sanitizeString($_POST['pw']);

if($user == "" || $pass == "")
    $error = "Not all fields were entered";
    }
else{
    $sql = "SELECT username, password FROM `Info` WHERE username = '$user'AND pass = '$pass'";
    $result = mysqli->query($sql);
if($result->num_rows == 0){
    $error = "Invalid login attempt";
    }
else {
    $_SESSION['un'] = $user;
    $_SESSION['pw'] = $pass;
    die("You are now logged in.");
    }
    }```

HP Parse error:  syntax error, unexpected '->' (T_OBJECT_OPERATOR) in /Applications/MAMP/htdocs/onsubmitlogin.php on line 17

I tried to read and debug the code myself but I don't recognize a syntactical error

Answer 1

我不知道您在哪里创建了数据库连接对象。在执行查询之前，您必须创建一个连接对象然后进行查询。示例：

$mysqli = new mysqli("your_host", "your_user", "your_password", "your_db_name");
$sql = "SELECT username, password FROM `Info` WHERE username = '$user'AND pass = '$pass'";
$result = $mysqli->query($sql);

您的代码有语法错误。代码行是：

$result = mysqli->query($sql);
//       ^^^^^^^

这里mysqli应该是连接对象。

为了清楚地理解reference。

还建议您bind您的参数来进行无风险（ SQL注入）查询。示例：

$stmt = $mysqli->prepare($sql);
$stmt->bind_param("ss", $user,$pass);
$stmt->execute();

获取PHP解析错误：语法错误，意外的'->'（T_OBJECT_OPERATOR）

1 个答案: