尝试PDO插入时出现意外的变量错误

Question

我已使用提供的链接切换到PDO并仅编写以下代码以获取引用包含插入的同一变量的错误。

解析错误：语法错误，意外T_ENCAPSED_AND_WHITESPACE，期待T_STRING或T_VARIABLE或T_NUM_STRING

此错误指的是$ stmt INSERT之后的行。

   <?php
   $servername = "XXXXXXXXXX";
   $username = "ymodb";
   $password = "XXXXXXXXX";
   $dbname = "ymodb";

   try {
   $conn = new PDO("mysql:host=$servername;dbname=$dbname", $username, $password);
   // set the PDO error mode to exception
   $conn->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);

   // prepare sql and bind parameters
   $stmt = $conn->prepare("INSERT INTO users (fullname, email, password, fname, email1, password1, relationship) VALUES ('$_POST['fullname']','$_POST['email']','$_POST['password']','$_POST['fname']','$_POST['email1']','$_POST['password1']','$_POST['relationship']')");
$stmt->execute();
echo "New records created successfully";
}
catch(PDOException $e)
{
echo "Error: " . $e->getMessage();
}
$conn = null;
?>