[PHP开发APP接口]⑨--单例模式连接数据库

Paste_Image.png

Paste_Image.png

Paste_Image.png

Paste_Image.png

Paste_Image.png

![Uploading Paste_Image_732324.png . . .]

Paste_Image.png

<?php

class Db{
    static private $_instance;
    static private $_connectSource;

    private $_dbConfig=array(
        'host'=>'127.0.0.1',
        'user'=>'root',
        'password'=>'123456',
        'database'=>'info'
    );

    private function __construct()
    {

    }

    static public function getInstance(){
        if(!(self::$_instance instanceof self)){
            self::$_instance=new Db();
        }
        return self::$_instance;
    }

    public function connect(){
        if(!self::$_connectSource) {
            self::$_connectSource = @mysql_connect($this->_dbConfig['host'], $this->_dbConfig['user'], $this->_dbConfig['password']);

            if (!self::$_connectSource) {
                die('mysql connect error  ' . mysql_error());
            }

            mysql_select_db($this->_dbConfig['database'],self::$_connectSource);
            mysql_query("set names UTF8", self::$_connectSource);
        }
        return self::$_connectSource;
    }

}

$connect=Db::getInstance()->connect();

$sql="select * from test";
$result=mysql_query($sql,$connect);
echo mysql_num_rows($result);
?>

Paste_Image.png