2015-03-19 create php alternative for myslq_result in mysqli(PHP)--PDO Tutorial for Mysql Developers

来源：http://www.bestwebframeworks.com/tutorials/php/152/create-php-alternative-for-mysql_result-in-mysqli/

内容：

If you are migrating from PHP 5.5 to a newer version of PHP - you might be interested in a MySQL to MySQLi/PDO migration guide - and use the function mysql_result() you might get a notice (in case your error_reporting is set to show deprecated warnings) that this function is deprecate. Since there is no 1:1 alternative you can build your own alternative in MySQLi like shown below：

代码：

      function mysqli_result($result,$row,$field =0){ 
             //adjust the result pointer to that specific row 
             $result->date_seek($row); 
             // Fetch rsult array 
             $data = $result->fetch_array(); 
             return $data[$field]; 
     } 

-----

PDO Tutorial for Mysql Developers

来源：http://wiki.hashphp.org/PDO_Tutorial_for_MySQL_Developers

why user pdo?

mysql_* functions are getting old. For a long time now mysql_* has been at odds with other common SQL database programing interface. It doesn't support modern SQL database concepts such as prepared statements,stored procs,transactions etc...

connectiong to mysql?

old way:

<?php

$link = mysql_connect('localhost','user','pass');

mysql_select_db('testdb',$link);

mysql_set_charset('UTF-8',$link);

new way :all you gotta do is create a new PDO object.

PDO's constructor takes at most 4 parameters--DSN,username,password, and an array of driver options.

A DSN is basically a string of options that tell PDO which driver to use,and the connection details...

<?php

$db = new PDO('mysql:host=localhost;dbname=testdb;charset=utf8','username','password');

NOTE:

If you get an error about character sets, make sure you add the chaset parameter to the DSN. Adding the charset to the DSN is very important for security reasons,most examples you'll see around leave it out.

MAKE SURE TO INCLUDE THE CHARSET

You can also pass in several driver options as an array to the fourth parameters.

 <?php
     $db = new PDO('mysql:host=localhost;dbname=testdb;charset=utf8', 'username', 'password', array(PDO::ATTR_EMULATE_PREPARES => false,                                                                                             PDO::ATTR_ERRMODE => PDO::ERRMODE_EXCEPTION)); 

you can also set some attributes after PDO construction with the setAttribute method:

<?php
$db = new PDO('mysql:host=localhost;dbname=testdb;charset=utf8', 'username', 'password');
$db->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
$db->setAttribute(PDO::ATTR_EMULATE_PREPARES, false

Error Handling

Consider your typical mysql_error handling

      <?php 
     //connected to mysql  
     $result = mysql_query("select * from table",$link) or die(mysql_error($link)); 

OR die is a pretty bad way to handle errors, yet this is typical mysql code.You can't handle die(); as it will just end the scipt abruptly and then echo the error to the screen which you usually do NOT want to show to your end users allowing nasty hackers discover your schema.

PDO has three error handling modes.

本文转自孤舟夜航之家博客51CTO博客，原文链接http://blog.51cto.com/cysky/1622129如需转载请自行联系原作者

cysky

本文来自互联网用户投稿，该文观点仅代表作者本人，不代表本站立场。本站仅提供信息存储空间服务，不拥有所有权，不承担相关法律责任。如若转载，请注明出处：http://www.mzph.cn/news/540318.shtml

如若内容造成侵权/违法违规/事实不符，请联系多彩编程网进行投诉反馈email:809451989@qq.com，一经查实，立即删除！