Mysqli-> insert_id没有返回任何内容

时间:2016-10-24 17:40:36

标签: php mysql mysqli

我正在创建一个使用PHP和MySQL的登录/注册页面,一切正常,但是当我尝试从MySQL检索insert_id时,它不起作用。即使我试图“打印”结果,它只会说1.继承我的代码:

这是我的联系:

<?
class Connection { //Connect to database
    /* Arguments */
    private $_host = "localhost";
    private $_username = ""; /* Change */
    private $_password = ""; /* Change */
    private $_database = "";
    private $_connection;
    private static $_instance;

    /* Methods */
    private function __construct(){ //Initial method
        $this->_connection=new mysqli($this->_host,$this->_username,$this->_password,$this->_database);
        if($this->_connection->connect_error){
           trigger_error("Error al conectar a base de datos: " . $this->_connection->connect_error);
        }
        $this->_connection->set_charset("utf8");
    }
    private function __clone(){} //Magic method
    public static function getInstance(){ //Get instance of connection
        if(!self::$_instance){
            self::$_instance=new self();
        }
        return self::$_instance;
    }
    public function getConnection(){ //Get MySQLi connection
        return $this->_connection;
    }
}

class Query extends Connection { //Query database
    public static function run($sql){
        return parent::getInstance()->getConnection()->query($sql);
    }
}
?>

这是我的用户类:

<?
class Users {
    /* Arguments */
    public static $result=NULL;

    /* Methods */
    public static function getDuplicated($sql){ //Get duplicated records
        $d=Query::run($sql);
        self::$result=$d->num_rows;
    }

    public static function createUser($sql){ //Create new user on database
        $c=Query::run($sql);
        self::$result=$c->insert_id;
    }
}
?>

最后这就是我称之为INSERT的地方:

<?
Users::$result=NULL;
$c=Users::createUser("INSERT INTO users (user,password,lastLogin) VALUES ('$username_register','$password_register',NOW())");
echo Users::$result;
?>

正如我所说的,一切正常,我可以从数据库中获取记录,它可以正确插入等等,但是当我使用insert-id时,它只是什么都没有。

1 个答案:

答案 0 :(得分:3)

您在insert_idmysqli_result)的结果中呼叫mysqli::query。你应该在mysqli对象上调用它。

您必须重构代码。也许是这样的:

class Query extends Connection { //Query database
   ...
   public static function lastInsertedId()
   {
       return parent::getInstance()->getConnection()->insert_id;
   }
}

...

$c=Query::run($sql);
echo Query::lastInsertedId();