Question

我现在来自.Net背景学习php。我想设置一种方法来在函数中使用我的数据库连接字符串，以便我可以调用它。我创建了一个类，只是想看看这是否正确完成或者我是否犯了任何错误。这是我的代码：

页面：module.php

// Database Connection Settings
$_SESSION['servername']     = "localhost";
$_SESSION['mysql_username'] = "user12345";
$_SESSION['mysql_password'] = "mypass12345";
$_SESSION['dbname']         = "dbnamehere";

class db_Class{
    function db_conn() {
        //global $conn;
        $conn = new mysqli($_SESSION['servername'], $_SESSION['mysql_username'], $_SESSION['mysql_password'], $_SESSION['dbname']);
        // Check connection
        if ($conn->connect_error) {
                die("Connection failed: " . $conn->connect_error);
        } 
        return $conn;
    }
}

页面：test.php

//Bring the class into the page for access.
include_once("module.php");
//Access our class.
$db_Class = new db_Class;
$conn = ($db_Class->db_conn());
//connect to the database.
$sql = "SELECT id, region FROM tbl_region;";
$result = $conn->query($sql);
//Print the results out.
if ($result->num_rows > 0) {
    // output data of each row
    while($row = $result->fetch_assoc()) {  
        echo '<td align="left" valign="top"><p>'.$row["region"].'</p></td></tr>';
    }
}

这是为PHP和数据库连接设置面向对象编程的正确方法吗？如果没有，请你解释我做错了什么？

Answer 1

database.php中

<?php 
class Database {
    const HOST = 'localhost';
    const USERNAME = 'root';
    const PASSWORD = 'root';
    const DATABASE = 'test';

    private static $instance;

    public static function getInstance()
    {
        if (!self::$instance) {
            self::$instance = new mysqli(Database::HOST, Database::USERNAME, Database::PASSWORD, Database::DATABASE);
            if (mysqli_connect_error()) {
                throw new Exception('Unable to connect to mysql server ' . mysqli_connect_error());
            }
        }
        return self::$instance;
    }
}

test.php的

//Bring the class into the page for access.
include_once("Database.php");

// Database Connection
$conn = Database::getInstance();
//connect to the database.
$sql = "SELECT id, region FROM tbl_region;";
$result = $conn->query($sql);
//Print the results out.
if ($result->num_rows > 0) {
    // output data of each row
    while($row = $result->fetch_assoc()) {  
        echo '<td align="left" valign="top"><p>'.$row["region"].'</p></td></tr>';
    }
}

这是PHP OOP的最佳方法

1 个答案: