PHP代码转换为PHP/MySQLi OOP

Question

今天我尝试将我的代码转换为PHP/MySQLi OOP代码。

class Database
{
private $host;
private $user;
private $password;
private $db;
private $mysqli;
function __construct()
{
    $this->host = "*****";
    $this->user = "*****";
    $this->password = "******";
    $this->db = "*****";
    $this->mysqli = new mysqli($this->host, $this->user, $this->password, $this->db);
    if (mysqli_connect_errno()):
        printf("Connect failed: %sn", mysqli_connect_error());
        exit();
    endif;
}
}

这是一个用于查询的脚本:

include_once("WD_Config/database.php");
class Adressen_Db
{
function __construct()
{
    $this->database = new Database();
}
public function selecteer()
{
    $query = "SELECT * FROM wd_adressen WHERE verborgen = 0 ORDER BY naam ASC";
    $result = $this->database->mysqli->query($query);
    return $result;
}
}

我就是这么叫它的

$adressen = new Adressen_Db;
$adressen_result = $adressen->selecteer();
echo "<p>";
while ($row = $adressen_result->fetch_assoc()):
echo "<a href='http://maps.google.com/?q=".$row['voladres']."'     target='_blank'>".$row['naam']."</a> woonachtig op <i>".$row['voladres']."</i><br>";
endwhile;
echo "</p>";

我总是得到"在非对象上调用成员函数query()"。不管我做什么都无所谓。

谁能告诉我这是为什么?

谢谢!

Answer 1

类Database中的$mysqli变量声明为private。

Answer 2

我认为，虽然你肯定需要将$mysqli作为公共的，所以它可以在其他方法中访问，可能还有其他的东西，因为错误会像

试图访问数据库类

中的私有属性

或类似的东西，而脚本抛出非对象调用错误

我认为你的new Adressen_Db;缺少括号:

$adressen = new Adressen_Db();

Answer 3

你可以这样替换你的代码:
config。

<?php
define("DB_HOST", "localhost");
define("DB_USER", "root");
define("DB_PASS", "");
define("DB_NAME", "your_database_name");

现在将此文件包含在数据库文件

require_once 'config.php';
Class Database {
    public $host = DB_HOST;
    public $user = DB_USER;
    public $pass = DB_PASS;
    public $dbname = DB_NAME;
    public $link;
    public $error;
    public function __construct() {
        $this->getConnection();
    }
    private function getConnection() {
        $this->link = new mysqli($this->host, $this->user, $this->pass, $this->dbname);
        if (!$this->link) {
            $this->error = "Connection failed" . $this->link->connect_error;
            return false;
        }
    }
    // for only select query
    public function select($query) {
        $result = $this->link->query($query) or
                die($this->link->error . __LINE__);
        if ($result->num_rows > 0) {
            return $result;
        } else {
            return false;
        }
    }
    // for insert, delete and update
    public function myquery($query) {
        $myquery = $this->link->query($query) or
                die($this->link->error . __LINE__);
        if ($myquery) {
            return $myquery;
        } else {
            return false;
        }
    }
}

现在，让你的查询像这样:

<?php
require_once './lib/Database.php';
?>
<?php
class Admin {
    private $db;
    public function __construct() {
        $this->db = new Database();
    }
    public function getData(){
        $query = "SELECT * FROM admin";
        $result = $this->db->select($query);
        if($result != false){
            while($row = $result->fetch_assoc()){
                // do your thing
            }
        }
    }
    public function insert(){
        $query = "INSERT INTO admin(admin_name) VALUES('$admin_name')";
        $result = $this->db->myquery($query);
        if($result){
            $msg = "User has been added successfully.";
            return $msg;
        } else {
            $msg = "Error while adding user. Please try again.";
            return $msg;
        }
    }
}

。