循环中的PHP - 没有停止

Question

我正在使用php while循环来读取结果,但它只是在第一条记录上不断循环,从不移动到第二条记录而且永远不会停止.我的代码:

class MySqlDatabase {   

    public function __construct() {
        $this->Open_Connection();
    }

    //Vars for Function Open_Connection
    private $_Connection;
    //Function Open_Connection - Connects to DB
    public function Open_Connection(){
        $this->_Connection = mysqli_connect('localhost','xxx','xxx','xxx');
        if(!$this->_Connection){
            die("Connection Failed: ". mysqli_error($this->_Connection));
        } else {
            echo "Success";
        }
    }

    //Vars for Function Query
    public $Results_Row;
    //Function Query - Runs Query and returns results 
    public function Query($Sql){
        $Results = mysqli_query($this->_Connection, $Sql);
        if(!$Results){
            die("Query Failed: ". mysqli_error($Results). "<br/>".$Sql);
        }
        $this->Results_Row = mysqli_fetch_row($Results);

        return $Results;
    }

}

$Db = new MySqlDatabase;

$Db->Query("SELECT * FROM Users");

while ($R = $Db->Results_Row){
    var_dump($R);
    echo "<hr/>";
}

这创建了永不停止的第一条记录的无限循环.我的数据库中只有两条记录,因此它应该在循环结束两个结果后停止.它再次只是保持无限循环第一条记录,永远不会移动到第二条记录然后停止.请帮助,谢谢.

Answer 1

你永远不会真正获取新行.您运行查询,然后访问第一行,然后一遍又一遍地引用该行.您需要在类中添加一个方法来获取行.

你需要这样的东西(未经测试的代码,基于你上面的内容):

class MySqlDatabase {   

    public function __construct() {
        $this->Open_Connection();
    }

    //Vars for Function Open_Connection
    private $_Connection;
    //Function Open_Connection - Connects to DB
    public function Open_Connection(){
        $this->_Connection = mysqli_connect('localhost','xxx','xxx','xxx');
        if(!$this->_Connection){
            die("Connection Failed: ". mysqli_error($this->_Connection));
        } else {
            echo "Success";
        }
    }

    public function FetchRow() { // I added this
        $this->Results_Row = mysqli_fetch_row($Results);
    }

    //Vars for Function Query
    public $Results_Row;
    //Function Query - Runs Query and returns results 
    public function Query($Sql){
        $Results = mysqli_query($this->_Connection, $Sql);
        if(!$Results){
            die("Query Failed: ". mysqli_error($Results). "<br/>".$Sql);
        }
        // I removed the mysqli_fetch_row() here to method FetchRow()

        return $Results;
    }

}

$Db = new MySqlDatabase;

$Db->Query("SELECT * FROM Users");

while ($R = $Db->FetchRow()){ // I changed this
    var_dump($R);
    echo "<hr/>";
}