PHP使用物件導向作Mysql查詢－King的幸福國度

物件導向的方式

通常我會寫兩個檔案，一個是DB_config.php，另外一個是DB.class.php

DB_config.php就是很簡單的設定database的位址、username、password以及使用的資料表

<?php
    global $_DB;	
    $_DB['host'] = "localhost";
    $_DB['username'] = "username";
    $_DB['password'] = "password";
    $_DB['dbname'] = "db_name";
?>

另外再寫一個DB_Class.php檔

<?php

class DB
{
    var $_dbConn = 0;
    var $_queryResource = 0;
    function DB(){
        //do nothing
    }
    function connect_db($host, $user, $pwd, $dbname){
        $dbConn = mysql_connect($host, $user, $pwd);
        if (! $dbConn)
            die ("MySQL Connect Error");
        mysql_query("SET NAMES utf8");
        if (! mysql_select_db($dbname, $dbConn))
            die ("MySQL Select DB Error");
        $this->_dbConn = $dbConn;
        return true;
    }
    function query($sql){
        if (! $queryResource = mysql_query($sql, $this->_dbConn))
            die ("MySQL Query Error");
        $this->_queryResource = $queryResource;
        return $queryResource;        
    }
    /** Get array return by MySQL */
    function fetch_array(){
        return mysql_fetch_array($this->_queryResource, MYSQL_ASSOC);
    }
    function fetch_row(){
        return mysql_fetch_row($this->_queryResource);
    }
    function get_num_rows(){
        return mysql_num_rows($this->_queryResource);
    }
    /** Get the cuurent id */    
    function get_insert_id(){
        return mysql_insert_id($this->_dbConn);
    } 
}

?>

最後在要使用mysql的php file裡面

<?php
    require_once("DB_config.php");
    require_once("DB.class.php");

    $db = new DB();
    $db->connect_db($_DB['host'], $_DB['username'], $_DB['password'], $_DB['dbname']);
    $db->query("SELECT ....");
    while($result = $db->fetch_array())
    {
        // do something you want...
        $result["欄位名稱"];
    }
?>