Question

我正在工作/学习如何mvc项目结构。我有一个数据库连接器，一个注册表类，一个模型和一个应用程序模型。我把所有这些都放在一个地方检查它是否正常工作。问题是我执行时会遇到这三个错误。

<?php

class db
{
    protected $conn;
    protected $host, $username, $password, $database;

    public function __construct($host, $username, $password, $database)
    {
        $this->conn = new mysqli($host, $username, $password, $database)
        OR die("There was a problem connecting to the database");

        return true;
    }

    public function query($sql)
    {
        $result = $this->conn->query($sql);
        if (!$result) {
            die('Invalid query:');
        }
        return $result;
    }

    public function escape($value)
    {
        return $this->conn->real_escape_string($value);
    }

    public function countAffected()
    {
        return $this->conn->affected_rows;
    }

    public function getLastId()
    {
        return $this->conn->insert_id;
    }

    public function __destruct()
    {
        $this->conn->close()
        OR die("Problem disconnecting from the database");
    }
}

final class registry
{
    private $data = array();

    public function get($key)
    {
        return (isset($this->data[$key]) ? $this->data[$key] : null);
    }

    public function set($key, $value)
    {
        $this->data[$key] = $value;
    }

    public function has($key)
    {
        return isset($this->data[$key]);
    }
}

abstract class Model
{
    protected $registry;

    public function __construct($registry)
    {
        $this->registry = $registry;  // Undefined variable: registry
    }

    public function __get($key)
    {
        return $this->registry->get($key);
    }

    public function __set($key, $value)
    {
        $this->registry->set($key, $value);
    }

}

class MemberModel extends Model
{
    public function getMember()
    {
        $result = $this->query("SELECT * FROM members"); //Call to undefined method MemberModel::query()
        return $result;
    }
}

// DB
define('DB_HOSTNAME', 'localhost');
define('DB_USERNAME', 'root');
define('DB_PASSWORD', '');
define('DB_DATABASE', 'pcaframework');

$registry = new registry();

// Database
$db = new db(DB_HOSTNAME, DB_USERNAME, DB_PASSWORD, DB_DATABASE);
$registry->set('db', $db);

$membermodel = new MemberModel(); //Missing argument 1 for Model::__construct()

$allMembers = $membermodel->getMember();

while ($row = mysqli_fetch_assoc($allMembers)) {
    echo "First Name: " . $row['name'] . "<br />";
    echo "Last Name: " . $row['email'] . "<br />";
    echo "<hr />";
}

缺少模型:: __ construct（）的参数1，调用$ membermodel = new MemberModel（）;
未定义的变量：registry
调用未定义的方法MemberModel :: query（）

我已对代码中的错误进行了评论，以准确标记错误发生的位置。

Answer 1

解决方案：

$result = $this->query("SELECT * FROM members"); //Call to undefined method MemberModel::query()

替换为：

$result = $this->conn->query("SELECT * FROM members");

你忘了＆＃34; - ＆gt; conn-＆gt;＆＃34;。

解决方案：

$this->registry = $registry;  // Undefined variable: registry

和

$membermodel = new MemberModel(); //Missing argument 1 for Model::__construct()

只需将$ last替换为$ registry var作为新类的参数：

$membermodel = new MemberModel($registry);

您正在调用需要参数的构造函数，但您并未引用该参数。

尝试从MySql加载数据时出错

1 个答案: