PHP单例模式实例,连接数据库对类的引用

最新推荐文章于 2025-09-13 19:07:06 发布

转载最新推荐文章于 2025-09-13 19:07:06 发布 · 214 阅读

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CC 4.0 BY-SA版权

原文链接：http://www.cnblogs.com/isuansuan/p/9759535.html

文章标签：

#数据库 #php

本文探讨了使用PHP实现的单例模式在数据库连接中的应用。通过定义静态成员变量和方法，确保了类的实例唯一性，有效管理了数据库资源。同时，展示了如何通过单例模式引用其他类。

<?php
//单例模式连接数据库
class pzhang{
    static private $instance;
    private static $config;
    private $dbase = array(
        'host' => 'localhost',
        'username' =>'root',
        'password'=>'root',
        'dbname' =>'jmyp'
    );
    private function __construct(){
    }
    static public function getInstance(){
         if(!self::$instance instanceof self)
             self::$instance  = new self();
         return self::$instance;
    }
    public function conn(){
        $mysql_db = $this->dbase['dbname'];
        self::$config = new mysqli($this->dbase['host'],$this->dbase['username'],$this->dbase['password']);
        self::$config->query('set name utf8');
        self::$config -> select_db($mysql_db);
        $sql = "select * from admin";
        $row = self::$config->query($sql);
        $data = [];
        while($tmp = $row->fetch_assoc()){
            $data[] = $tmp;
        }
        echo "<pre>";
        print_r($data);
        echo "</pre>";
        return self::$config;
    }
}
$obj = pzhang::getInstance();
$obj->conn();

//单例模式对类的引用
class zhangp{
    public function system(){
        echo "learning more";
    }
}

class singleCase{
    static private $instance;
    private $avg;
    private function __construct($config){
        self::$instance = new $config;
    }
    static public function getInstance($avg){
        if(!self::$instance instanceof self)
             new self($avg);
        return self::$instance;
    }
}
$obj = singleCase::getInstance('zhangp');
$obj->system();
?>