28）PHP，数据库连接类

 1 <?php
 2 //类名，也习惯上（推荐）使用跟文件名相似的名字
 3 //定义一个类，该类可以连接mysql数据库
 4 //并连接后返回资源（或失败就终止）
 5 class mysqlDB{
 6     public $host;
 7     public $port;
 8     public $username;
 9     public $password;
10     public $charset;
11     public $dbname;
12 
13     //连接结果（资源）
14     static $link;
15     
16     //构造函数
17     public function __construct($config){
18         //初始化数据
19         $this->host = isset($config[‘host‘]) ? $config[‘host‘] : ‘localhost‘;
20         $this->port = isset($config[‘port‘]) ? $config[‘port‘] : ‘3306‘;
21         $this->username = isset($config[‘username‘]) ? $config[‘username‘] : ‘root‘;
22         $this->password = isset($config[‘password‘]) ? $config[‘password‘] : ‘‘;
23         $this->charset = isset($config[‘charset‘]) ? $config[‘charset‘] : ‘utf8‘;
24         $this->dbname = isset($config[‘dbname‘]) ? $config[‘dbname‘] : ‘‘;
25 
26         //连接数据库
27         self::$link = $this->connect();
28         //设定连接编码
29         $this->setCharset($this->charset);
30         //选定数据库
31         $this->selectDb($this->dbname);
32     }
33     //这里进行连接
34     public function connect(){
35         $link = mysql_connect("$this->host:$this->port", "$this->username","$this->password") or die("连接数据库失败！");
36         return $link;
37     }
38     public function setCharset($charset){
39         mysql_set_charset($charset, self::$link); 
40     }
41     public function selectDb($dbname){
42         mysql_select_db($dbname, self::$link) 
43     }
44 }
45 
46 //先设想：
47 $config = array(
48     ‘host‘=>‘localhost‘,
49     ‘port‘=>‘3306‘,
50     ‘username‘=>‘root‘,
51     ‘password‘=>‘123‘,
52     ‘charset‘=>‘utf8‘,
53     ‘dbname‘=>‘php34‘,
54     );
55 $link = new mysqlDB( $config );
56 $result = $link->query("delete from tab1 where id=1");