MySQL支持Select和某些Update和Delete情况下的Join语法，具体语法上的细节有：
table_reference [, table_reference] …
table_factor
| join_table
tbl_name [[AS] alias]
[{USE|IGNORE|FORCE} INDEX (key_list)]
| ( table_references )
mysql多表联结查询 18 June 2010 16:18 Friday by 小屋 浏览(1946)
开源 PHP 验证码 Securimage 带语音识别 05 May 2010 22:11 Wednesday by小屋 浏览(1868)
官方网站：http://www.phpcaptcha.org/
下载地址：http://www.phpcaptcha.org/download/
原文地址：http://www.21andy.com/blog/20100417/1886.html
验证码图 片：
<img id="captcha" src="/securimage/securimage_show.php" alt="CAPTCHA Image" />
验证码文 本框：
<input type="text" name="captcha_code" size="10" maxlength="6" />
看不清验证码：
<a href="#" rel="nofollow" target="_blank">Reload Image</a>
后端PHP验 证：
<?php
session_start();
include_once $_SERVER['DOCUMENT_ROOT'] . '/securimage/securimage.php';
$securimage = new Securimage();
if ($securimage->check($_POST['captcha_cod
session_start();
include_once $_SERVER['DOCUMENT_ROOT'] . '/securimage/securimage.php';
$securimage = new Securimage();
if ($securimage->check($_POST['captcha_cod