$table_name=strval($new_username).'_msgs';
@ $db=new mysqli('localhost','root','','newdatabase');
$query2="CREATE TABLE ? ( 'msg_id' int(20) auto_increment primary key,'sender' varchar(50), 'content' varchar(2000), 'date' varchar(50) )";
$stmt2=$db->prepare($query2);
$stmt2->bind_param("s",$table_name);
$stmt2->execute();
它给出此错误消息“调用非对象上的成员函数 bind_param()”