我们今天为大家介绍的是关于下面我们就通过实例来说明使用PHP面向对象编程的实际意义和应用方法。
我们通常在做一个有数据库后台的网站的时候，都会考虑到程序需要适用于不同的应用环境。和其他编程语言有所不同的是，在PHP中，操作数据库的是一系列的具体功能函数（如果你不使用ODBC接口的话）。这样做虽然效率很高，但是封装却不够。如果有一个统一的数据库接口，那么我们就可以不对程序做任何修改而适用于多种数据库，从而使程序的移植性和跨平台能力都大大提高。
PHP面向对象编程的完成，需要进行对象封装，也就是编写类。我们可以通过生成一个新的SQL类实现对数据库的简单封装。例如：
<ol class="dp-xml">
<li class="alt"><span><span class="tag"><strong><font color="#006699"></font></strong></span><span> ? </span></span></li>
<li class=""><span>class SQL </span></li>
<li class="alt"><span>{ </span></li>
<li class=""><span>var $Driver; //实际操作的数据库驱动子类 </span></li>
<li class="alt"><span>var $connection; //共用的数据库连接变量 </span></li>
<li class=""><span>function DriverRegister($d) </span></li>
<li class="alt"><span>{ </span></li>
<li class=""><span>if($d!="") </span></li>
<li class="alt"><span>{ </span></li>
<li class="">
<span>$</span><span class="attribute"><font color="#ff0000">include_path</font></span><span> = </span><span class="attribute-value"><font color="#0000ff">ini_get</font></span><span>("include_path"); </span>
</li>
<li class="alt">
<span>$</span><span class="attribute"><font color="#ff0000">DriverFile</font></span><span> = $include_path."/".$d.".php"; </span>
</li>
<li class=""><span>//驱动的存放路径必须在PHP.ini文件中设定的INCLUDE_PATH下 </span></li>
<li class="alt"><span>if( file_exists( $DriverFile)) //查找驱动是否存在 </span></li>
<li class=""><span>{ </span></li>
<li class="alt"><span>include($DriverFile); </span></li>
<li class="">
<span>$this-</span><span class="tag"><strong><font color="#006699">></font></strong></span><span class="attribute"><font color="#ff0000">Driver</font></span><span> = </span><span class="attribute-value"><font color="#0000ff">new</font></span><span> $d(); </span>
</li>
<li class="alt"><span>// 根据驱动名称生成相应的数据库驱动类 </span></li>
<li class=""><span>return true; </span></li>
<li class="alt"><span>} </span></li>
<li class=""><span>} </span></li>
<li class="alt"><span>return false; //注册驱动失败 </span></li>
<li class=""><span>} </span></li>
<li class="alt"><span>function Connect($host,$user,$passwd,$database)//连接数据库的函数 </span></li>
<li class=""><span>{ </span></li>
<li class="alt">
<span>$this-</span><span class="tag"><strong><font color="#006699">></font></strong></span><span>Driver-</span><span class="tag"><strong><font color="#006699">></font></strong></span><span class="attribute"><font color="#ff0000">host</font></span><span>=$host; </span>
</li>
<li class="">
<span>$this-</span><span class="tag"><strong><font color="#006699">></font></strong></span><span>Driver-</span><span class="tag"><strong><font color="#006699">></font></strong></span><span class="attribute"><font color="#ff0000">user</font></span><span>=$user; </span>
</li>
<li class="alt">
<span>$this-</span><span class="tag"><strong><font color="#006699">></font></strong></span><span>Driver-</span><span class="tag"><strong><font color="#006699">></font></strong></span><span class="attribute"><font color="#ff0000">passwd</font></span><span>=$pas </span>
</li>
<li class=""><span>swd; </span></li>
<li class="alt">
<span>$this-</span><span class="tag"><strong><font color="#006699">></font></strong></span><span>Driver-</span><span class="tag"><strong><font color="#006699">></font></strong></span><span class="attribute"><font color="#ff0000">database</font></span><span>=$d </span>
</li>
<li class=""><span>atabase; </span></li>
<li class="alt">
<span>$this-</span><span class="tag"><strong><font color="#006699">></font></strong></span><span class="attribute"><font color="#ff0000">connection</font></span><span> = $this-</span><span class="tag"><strong><font color="#006699">></font></strong></span><span>Driver-</span><span class="tag"><strong><font color="#006699">></font></strong></span><span>Connect(); </span>
</li>
<li class=""><span>} </span></li>
<li class="alt"><span>function Close()//关闭数据库函数 </span></li>
<li class=""><span>{ </span></li>
<li class="alt">
<span>$this-</span><span class="tag"><strong><font color="#006699">></font></strong></span><span>Driver-</span><span class="tag"><strong><font color="#006699">></font></strong></span><span>close($this-</span><span class="tag"><strong><font color="#006699">></font></strong></span><span>connection); </span>
</li>
<li class=""><span>} </span></li>
<li class="alt"><span>function Query($queryStr)//数据库字符串查询函数 </span></li>
<li class=""><span>{ </span></li>
<li class="alt">
<span>return $this-</span><span class="tag"><strong><font color="#006699">></font></strong></span><span>Driver-</span><span class="tag"><strong><font color="#006699">></font></strong></span><span>query($queryStr,$this-</span><span class="tag"><strong><font color="#006699">></font></strong></span><span>connection); </span>
</li>
<li class=""><span>} </span></li>
<li class="alt"><span>function getRows($res)//查找行 </span></li>
<li class=""><span>{ </span></li>
<li class="alt">
<span>return $this-</span><span class="tag"><strong><font color="#006699">></font></strong></span><span>Driver-</span><span class="tag"><strong><font color="#006699">></font></strong></span><span>getRows($res); </span>
</li>
<li class=""><span>} </span></li>
<li class="alt"><span>function getRowsNum($res)//取得行号 </span></li>
<li class=""><span>{ </span></li>
<li class="alt">
<span>return $this-</span><span class="tag"><strong><font color="#006699">></font></strong></span><span>Driver-</span><span class="tag"><strong><font color="#006699">></font></strong></span><span> getRowsNum ($res); </span>
</li>
<li class=""><span>} </span></li>
<li class="alt"><span>} </span></li>
<li class="">
<span>? </span><span class="tag"><strong><font color="#006699">></font></strong></span><span> </span>
</li>
</ol>希望以上介绍的PHP面向对象编程的相关知识对大家有所帮助。
