Gemeinschaft Lernen Tools-Bibliothek Freizeit
suchen
Deutsch
Heim > Backend-Entwicklung > PHP-Tutorial > Hauptteil

PHP新手之编程快速入门_PHP教程

WBOY
Freigeben： 2016-07-20 10:57:44
Original
1126 Leute haben es durchsucht

面向对象编程（OOP)是我们编程的一项基本技能，PHP4对OOP提供了良好的支持。如何使用OOP的思想来进行PHP的高级编程，对于提高PHP编程能力和规划好Web开发构架都是非常有意义的。下面我们就通过实例来说明使用PHP的OOP进行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。

在PHP中要完成OOP，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-c">
<li class="alt"><span><span><span class="keyword">class</span><span> SQL { </span><span class="keyword">var</span><span> </span><span class="vars">$Driver</span><span>;   </span></span></span></li>
<li>
<span class="comment">//实际操作的数据库驱动子类  </span><span> </span>
</li>
<li class="alt">
<span class="keyword">var</span><span> </span><span class="vars">$connection</span><span>;   </span>
</li>
<li>
<span class="comment">//共用的数据库连接变量  </span><span> </span>
</li>
<li class="alt">
<span class="keyword">function</span><span> DriverRegister(</span><span class="vars">$d</span><span>) {   </span>
</li>
<li>
<span class="keyword">if</span><span>(</span><span class="vars">$d</span><span>!=</span><span class="string">""</span><span>) { </span><span class="vars">$include_path</span><span> = </span><span class="func">ini_get</span><span>(</span><span class="string">"include_path"</span><span>);   </span>
</li>
<li class="alt">
<span class="vars">$DriverFile</span><span> = </span><span class="vars">$include_path</span><span>.</span><span class="string">"/"</span><span>.</span><span class="vars">$d</span><span>.</span><span class="string">".php"</span><span>;   </span>
</li>
<li>
<span class="comment">//驱动的存放路径必须在PHP.ini文件中设定的INCLUDE_PATH下  </span><span> </span>
</li>
<li class="alt">
<span class="keyword">if</span><span>( </span><span class="func">file_exists</span><span>( </span><span class="vars">$DriverFile</span><span>)) </span><span class="comment">//查找驱动是否存在  </span><span> </span>
</li>
<li><span>{   </span></li>
<li class="alt">
<span class="keyword">include</span><span>(</span><span class="vars">$DriverFile</span><span>); </span><span class="vars">$this</span><span>->Driver = </span><span class="keyword">new</span><span> </span><span class="vars">$d</span><span>();   </span>
</li>
<li>
<span class="comment">// 根据驱动名称生成相应的数据库驱动类  </span><span> </span>
</li>
<li class="alt">
<span class="keyword">return</span><span> true;   </span>
</li>
<li><span>}   </span></li>
<li class="alt"><span>}   </span></li>
<li>
<span class="keyword">return</span><span> false;   </span>
</li>
<li class="alt">
<span class="comment">//注册驱动失败  </span><span> </span>
</li>
<li><span>}   </span></li>
<li class="alt">
<span class="keyword">function</span><span> Connect(</span><span class="vars">$host</span><span>,</span><span class="vars">$user</span><span>,</span><span class="vars">$passwd</span><span>,</span><span class="vars">$database</span><span>)  </span>
</li>
<li>
<span class="comment">//连接数据库的函数  </span><span> </span>
</li>
<li class="alt">
<span>{ </span><span class="vars">$this</span><span>->Driver->host=</span><span class="vars">$host</span><span>;   </span>
</li>
<li>
<span class="vars">$this</span><span>->Driver->user=</span><span class="vars">$user</span><span>;   </span>
</li>
<li class="alt">
<span class="vars">$this</span><span>->Driver->passwd=</span><span class="vars">$pas</span><span> swd;   </span>
</li>
<li>
<span class="vars">$this</span><span>->Driver->database=</span><span class="vars">$d</span><span> atabase;   </span>
</li>
<li class="alt">
<span class="vars">$this</span><span>->connection = </span><span class="vars">$this</span><span>->Driver->Connect();   </span>
</li>
<li><span>}   </span></li>
<li class="alt">
<span class="keyword">function</span><span> Close()  </span>
</li>
<li>
<span class="comment">//关闭数据库函数  </span><span> </span>
</li>
<li class="alt"><span>{   </span></li>
<li>
<span class="vars">$this</span><span>->Driver->close(</span><span class="vars">$this</span><span>->connection);   </span>
</li>
<li class="alt"><span>}   </span></li>
<li>
<span class="keyword">function</span><span> Query(</span><span class="vars">$queryStr</span><span>)  </span>
</li>
<li class="alt">
<span class="comment">//数据库字符串查询函数 {  </span><span> </span>
</li>
<li>
<span class="keyword">return</span><span> </span><span class="vars">$this</span><span>->Driver->query(</span><span class="vars">$queryStr</span><span>,</span><span class="vars">$this</span><span>->connection);   </span>
</li>
<li class="alt"><span>}   </span></li>
<li>
<span class="keyword">function</span><span> getRows(</span><span class="vars">$res</span><span>)  </span>
</li>
<li class="alt">
<span class="comment">//查找行  </span><span> </span>
</li>
<li><span>{   </span></li>
<li class="alt">
<span class="keyword">return</span><span> </span><span class="vars">$this</span><span>->Driver->getRows(</span><span class="vars">$res</span><span>);   </span>
</li>
<li><span>}   </span></li>
<li class="alt">
<span class="keyword">function</span><span> getRowsNum(</span><span class="vars">$res</span><span>)  </span>
</li>
<li>
<span class="comment">//取得行号  </span><span> </span>
</li>
<li class="alt"><span>{   </span></li>
<li>
<span class="keyword">return</span><span> </span><span class="vars">$this</span><span>->Driver-> getRowsNum (</span><span class="vars">$res</span><span>);   </span>
</li>
<li class="alt"><span>}   </span></li>
<li><span>}   </span></li>
<li class="alt"><span>? >  </span></li>
</ol>
Nach dem Login kopieren

我们以操作MySQL数据库为例。我们写一个数据库驱动类MySQL，在该类中，我们把有关MySQL数据库操作的函数都做进一步的封装。把包含该类，文件名为MySQL.php的文件放在PHP的系统 include_path下，就可以正常地使用了。注意编写数据库驱动文件时，文件名应和类名保持一致。

<ol class="dp-c">
<li class="alt"><span><span><span class="keyword">var</span><span> </span><span class="vars">$host</span><span>; </span><span class="keyword">var</span><span> </span><span class="vars">$user</span><span>; </span><span class="keyword">var</span><span> </span><span class="vars">$passwd</span><span>; </span><span class="keyword">var</span><span> </span><span class="vars">$database</span><span>;   </span></span></span></li>
<li>
<span class="keyword">function</span><span> MySQL()   </span>
</li>
<li class="alt">
<span class="comment">//利用构造函数实现变量初始化  </span><span> </span>
</li>
<li>
<span>{ </span><span class="vars">$host</span><span> = </span><span class="string">""</span><span>;   </span>
</li>
<li class="alt">
<span class="vars">$user</span><span> = </span><span class="string">""</span><span>;   </span>
</li>
<li>
<span class="vars">$passwd</span><span> = </span><span class="string">""</span><span>;   </span>
</li>
<li class="alt">
<span class="vars">$database</span><span> = </span><span class="string">""</span><span>;   </span>
</li>
<li><span>}   </span></li>
<li class="alt">
<span class="keyword">function</span><span> Connect()   </span>
</li>
<li>
<span>{ </span><span class="vars">$conn</span><span> = MySQL_connect(</span><span class="vars">$this</span><span>->host, </span><span class="vars">$this</span><span>->user,</span><span class="vars">$this</span><span>->passwd) </span>
</li>
<li>
<span class="keyword">or</span><span> </span><span class="keyword">die</span><span>(</span><span class="string">"Could not connect to $this->host"</span><span>);   </span>
</li>
<li class="alt">
<span>MySQL_select_db(</span><span class="vars">$this</span><span>->database,</span><span class="vars">$conn</span><span>) </span><span class="keyword">or</span><span> </span><span class="keyword">die</span><span>(</span><span class="string">"Could not switch to database $this->database;"</span><span>);   </span>
</li>
<li>
<span class="keyword">return</span><span> </span><span class="vars">$conn</span><span>;   </span>
</li>
<li class="alt"><span>}   </span></li>
<li>
<span class="keyword">function</span><span> Close(</span><span class="vars">$conn</span><span>) {   </span>
</li>
<li class="alt">
<span>MySQL_close(</span><span class="vars">$conn</span><span>);   </span>
</li>
<li><span>}   </span></li>
<li class="alt">
<span class="keyword">function</span><span> Query(</span><span class="vars">$queryStr</span><span>, </span><span class="vars">$conn</span><span>)   </span>
</li>
<li><span>{   </span></li>
<li class="alt">
<span class="vars">$res</span><span> =MySQL_query(</span><span class="vars">$queryStr</span><span>, </span><span class="vars">$conn</span><span>) </span><span class="keyword">or</span><span> </span><span class="keyword">die</span><span>(</span><span class="string">"Could not query database"</span><span>);   </span>
</li>
<li>
<span class="keyword">return</span><span> </span><span class="vars">$res</span><span>;   </span>
</li>
<li class="alt"><span>}   </span></li>
<li>
<span class="keyword">function</span><span> getRows(</span><span class="vars">$res</span><span>)   </span>
</li>
<li class="alt"><span>{   </span></li>
<li>
<span class="vars">$rowno</span><span> = 0;   </span>
</li>
<li class="alt">
<span class="vars">$rowno</span><span> = MySQL_num_rows(</span><span class="vars">$res</span><span>);   </span>
</li>
<li>
<span class="keyword">if</span><span>(</span><span class="vars">$rowno</span><span>>0)   </span>
</li>
<li class="alt"><span>{   </span></li>
<li>
<span class="keyword">for</span><span>(</span><span class="vars">$row</span><span>=0;</span><span class="vars">$row</span><span><span class="vars">$rowno</span><span>;</span><span class="vars">$row</span><span>++)   </span></span>
</li>
<li class="alt"><span>{   </span></li>
<li>
<span class="vars">$rows</span><span>[</span><span class="vars">$row</span><span>]=MySQL_fetch_row(</span><span class="vars">$res</span><span>);   </span>
</li>
<li class="alt"><span>}   </span></li>
<li>
<span class="keyword">return</span><span> </span><span class="vars">$rows</span><span>;   </span>
</li>
<li class="alt"><span>}   </span></li>
<li><span>}   </span></li>
<li class="alt">
<span class="keyword">function</span><span> getRowsNum(</span><span class="vars">$res</span><span>)   </span>
</li>
<li><span>{   </span></li>
<li class="alt">
<span class="vars">$rowno</span><span> = 0;   </span>
</li>
<li>
<span class="vars">$rowno</span><span> = mysql_num_rows(</span><span class="vars">$res</span><span>); </span><span class="keyword">return</span><span> </span><span class="vars">$rowno</span><span>;   </span>
</li>
<li class="alt"><span>} } ? >  </span></li>
</ol>
Nach dem Login kopieren

同样我们要封装其他的“数据库驱动”到我们的SQL类中，只需要建立相应的类，并以同名命名驱动文件，放到PHP的include目录就可以了。

完成封装以后，就可以在PHP中按照OOP的思想来实现对数据库的编程了。

<ol class="dp-c">
<li class="alt"><span><span></span></span></li>
<li>
<span class="vars">$sql</span><span> = </span><span class="keyword">new</span><span> SQL;   </span>
</li>
<li class="alt">
<span class="comment">//生成新的Sql对象  </span><span> </span>
</li>
<li>
<span class="keyword">if</span><span>(</span><span class="vars">$sql</span><span>-> DriverRegister(“MySQL”))   </span>
</li>
<li class="alt">
<span class="comment">//注册数据库驱动  </span><span> </span>
</li>
<li><span>{   </span></li>
<li class="alt">
<span class="vars">$sql</span><span>->Connect(“localhost”,”root”,””,”test”);   </span>
</li>
<li>
<span class="vars">$res</span><span>=</span><span class="vars">$sql</span><span>->query(“select * from test”);   </span>
</li>
<li class="alt">
<span class="comment">//返回查询记录集  </span><span> </span>
</li>
<li>
<span class="vars">$rowsnum</span><span> = </span><span class="vars">$sql</span><span>->getRowsNum(</span><span class="vars">$res</span><span>);   </span>
</li>
<li class="alt">
<span class="keyword">if</span><span>(</span><span class="vars">$rowsnum</span><span> > 0) {   </span>
</li>
<li>
<span class="vars">$rows</span><span> = </span><span class="vars">$sql</span><span>->getRows(</span><span class="vars">$res</span><span>);   </span>
</li>
<li class="alt">
<span class="keyword">foreach</span><span>(</span><span class="vars">$rows</span><span> </span><span class="keyword">as</span><span> </span><span class="vars">$row</span><span>)   </span>
</li>
<li>
<span class="comment">//循环取出记录集内容 {  </span><span> </span>
</li>
<li class="alt">
<span class="keyword">foreach</span><span>(</span><span class="vars">$row</span><span> </span><span class="keyword">as</span><span> </span><span class="vars">$field</span><span>){ print </span><span class="vars">$field</span><span>;} } } </span><span class="vars">$sql</span><span>->Close();   </span>
</li>
<li><span>} ?　>  </span></li>
</ol>
Nach dem Login kopieren

在实际应用中，我们还可以根据实际需求对各种对象类做进一步扩展。在PHP中，还提供了一系列复杂的OOP方法，例如继承，重载，引用，串行化等等。充分调动各种方法并灵活运用，就能够使你的网站更合理和结构化，开发和维护也更容易。

希望通过以上内容的介绍，能给你带来帮助。


www.bkjia.comtruehttp://www.bkjia.com/PHPjc/445751.htmlTechArticle面向对象编程 （OOP)是我们编程的一项基本技能， PHP 4对OOP提供了良好的支持。如何使用OOP的思想来进行PHP的高级编程，对于提高PHP编程能...
Verwandte Etiketten：
oop php 入门 基本 对 对象 快速 我们 技能 提供 新手 是 的 编程 面向
Quelle：php.cn
Vorheriger Artikel：Perl、PHP、Python、Java和Ruby的比较_PHP教程 Nächster Artikel：PHP新手之PHP数组变量的使用_PHP教程
Erklärung dieser Website
Der Inhalt dieses Artikels wird freiwillig von Internetnutzern beigesteuert und das Urheberrecht liegt beim ursprünglichen Autor. Diese Website übernimmt keine entsprechende rechtliche Verantwortung. Wenn Sie Inhalte finden, bei denen der Verdacht eines Plagiats oder einer Rechtsverletzung besteht, wenden Sie sich bitte an admin@php.cn
Neueste Artikel des Autors
Aktuelle Ausgaben
Aus URL-Parametern erhaltene PHP-Arrays verhalten sich nicht wie erwartet Ich habe einen URL-Parameter, der die Kategorie-ID enthält, und ich möchte ihn als Array w...
Aus 2024-04-06 22:09:02
0
1
1428
Wo soll ich die CustomLog-Direktive in Apache platzieren? Ich verwende php:7.2-apachedocker. Ich muss das URL-Anmeldezugriffsprotokoll zur Gesundhei...
Aus 2024-04-06 22:03:59
0
1
990
Welches Format haben die Variablen im Rückgabewert? Ich bin ein PHP-Neuling. Ich habe einen Code gefunden: if($x<time()){return[false,'erro...
Aus 2024-04-06 21:55:20
0
1
778
Bei der Verwendung von opentbs zum Generieren von ODT-Dateien sind Probleme aufgetreten: Werte desselben Schlüssels werden in derselben Zeile statt in separaten Spalten angezeigt. Ich verwende eine Bibliothek namens OpenTbs, um ODT mit PHP zu erstellen. Ich verwende sie...
Aus 2024-04-06 20:18:18
0
1
483
Gruppieren Sie MySQL-Ergebnisse nach ID für die Schleife Ich habe eine Tabelle mit Flugdaten in MySQL. Ich schreibe einen PHP-Code, der Daten mithi...
Aus 2024-04-06 17:27:56
0
1
406
verwandte Themen
Mehr>
Beliebte Empfehlungen
Beliebte Tutorials
Mehr>
Verwandte Tutorials
Beliebte Empfehlungen
Aktuelle Kurse
Neueste Downloads
Mehr>
Web-Effekte
Quellcode der Website
Website-Materialien
Frontend-Vorlage