简单的数据库链式操作的例子

<?php 

/* 

@author Dishy 
数据库封装 
*/ 
class mysqldb{

private $host;
private $username;
private $password;
private $dbname;
private $sql;
private $select = true;
private $result;
private $array;

public function __construct($host,$username,$password,$dbname){
    $this->host = $host;
    $this->username = $username;
    $this->password = $password;
    $this->dbname = $dbname;
    $this->dbconnect();

}
/* 数据库连接 */
private function dbconnect(){
    mysql_connect($this->host,$this->username,$this->password);
    mysql_select_db($this->dbname);

}
/* *执行sql语句 * **/
public function query($sql){
        $this->sql = $sql;
        $this->result = mysql_query($this->sql);
        return $this;
}
/* * *$select = false时输出sql语句 */
public function select($select= true){
    $this->select = $select;
    if($this->select){
        return $this->array =  $this->result();
    }else{
        return $this->sql;
    }
}
/** *结果集 */
private function result(){
    $array = mysql_fetch_array($this->result);
    return $array;
}

}

?> 
使用方法 include “./Api/datebase.php”; 
define('DB_HOST_NAME','localhost'); 
define('DB_HOST_USERNAME','root'); 
define('DB_HOST_PASSWORD','root'); 
define('DB_HOST_DB','jciot'); 
$Jciot_db = new mysqldb(DB_HOST_NAME,DB_HOST_USERNAME,DB_HOST_PASSWORD,DB_HOST_DB); 
$a = $Jciot_db->query('select * from jciot_member')->select(); 
var_dump($a);

?>`