blocks|key|586345|text|你不需要初始化它。最好将其配置为|type|unstyled|depth|inlineStyleRanges|entityRanges|data|586346|像这样的application+-+config+-+autoload.php文件|offset|length|style|CODE|586347|+++$autoload['libraries']+=+array('database');|code-block|syntax|javascript|586348|entityMap^0|0|4|Z|0|0^^$0|@$1|2|3|4|5|6|7|O|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|P|8|@$D|Q|E|R|F|G]]|9|@]|A|$]]|$1|H|3|I|5|J|7|S|8|@]|9|@]|A|$K|L]]|$1|M|3|-4|5|6|7|T|8|@]|9|@]|A|$]]]|N|$]]

you dont need to initialize that . better configure it into 
<code>application - config - autoload.php</code> file like this 

<pre><code> $autoload['libraries'] = array('database');
</code></pre>

blocks|key|817489|text|加载数据库对象的代码行是：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|817490|$this->load->database();|code-block|syntax|javascript|817491|然后使用名称db引用数据库对象，如下所示：|817492|$this->db->method_name();|817493|正如前一篇文章所指出的，如果你打算跨多个模型使用数据库，你应该在你的autoload.php配置文件中自动加载库。|817494|entityMap^0|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|O|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|P|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|Q|8|@]|9|@]|A|$]]|$1|I|3|J|5|D|7|R|8|@]|9|@]|A|$E|F]]|$1|K|3|L|5|6|7|S|8|@]|9|@]|A|$]]|$1|M|3|-4|5|6|7|T|8|@]|9|@]|A|$]]]|N|$]]

The line of code to load the database object is:

<pre><code>$this-&gt;load-&gt;database();
</code></pre>

The database object is then referenced with the name db like so:

<pre><code>$this-&gt;db-&gt;method_name();
</code></pre>

As pointed out by the previous post, if you are going to use the database across multiple models, you should have the library autoloaded in your autoload.php config file.

blocks|key|218763|text|您是在父类的构造函数之前还是之后执行此操作？|type|unstyled|depth|inlineStyleRanges|entityRanges|data|218764|public+function+__construct()
{
++++//+placing+it+here+fails:+$this+has+no+`load`+property+yet.
++++//+$this->load->database();+<!--+NO+WAY+JOSÉ!
++++parent::__construct();
++++//+placing+it+here+should+work+as+the+parent+class+has+added+that+property
++++//+during+it's+own+constructor
++++$this->load->database();
}|code-block|syntax|javascript|218765|另一方面，您可以更明确地表示：|218766|public+function+__construct()
{
++++//+Doesn't+matter+where+this+goes:
++++//+grab+the+controller+directly
++++$CI+=&+get_instance();+//+&+is+not+strictly+necessary,+but+still...
++++//+force+the+loader+to+load+the+database.
++++$CI->load->database();
++++//+directly+assign+it.
++++$this->db+=+$CI->db;
++++//+continue+on+your+merry+way
++++parent::__construct();
}|218767|218768|entityMap^0|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|N|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|O|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|P|8|@]|9|@]|A|$]]|$1|I|3|J|5|D|7|Q|8|@]|9|@]|A|$E|F]]|$1|K|3|-4|5|6|7|R|8|@]|9|@]|A|$]]|$1|L|3|-4|5|6|7|S|8|@]|9|@]|A|$]]]|M|$]]

Are you doing that before or after the parent class's constructor?

<pre><code>public function __construct()
{
 // placing it here fails: $this has no `load` property yet.
 // $this-&gt;load-&gt;database(); &lt;!-- NO WAY JOSÉ!
 parent::__construct();
 // placing it here should work as the parent class has added that property
 // during it's own constructor
 $this-&gt;load-&gt;database();
}
</code></pre>

On the other hand, you could be even more explicit:

<pre><code>public function __construct()
{
 // Doesn't matter where this goes:
 // grab the controller directly
 $CI =&amp; get_instance(); // &amp; is not strictly necessary, but still...
 // force the loader to load the database.
 $CI-&gt;load-&gt;database();
 // directly assign it.
 $this-&gt;db = $CI-&gt;db;
 // continue on your merry way
 parent::__construct();
}
</code></pre>

I believe the explicit solution solved a number of problems in a PHP 4 project once, but it is technically overkill.

I am putting this code in the constructor for a model class, based on teh tutorial for CI, it states that if you put it there, the database connection can be used globally within that class afterwards. For some reason it's not working and the application crashes at that part of the code. My database configuration is fine since when i put it in the controller i'm able to get db info fine.

$this->load->db(); initialize in class constructor?

翻译质量差，导致语言生硬或混乱。

没有提供实际的解决方法或示例。

解答不清晰，无法理解或解决问题。

页面排版不美观，阅读体验差。

文章

问答

视频

学习中心

腾讯云实验室

直播

竞赛

腾讯云代码分析专区

腾讯iOA零信任安全管理系统专区

腾讯云架构师技术同盟交流圈

腾讯云数据库专区

腾讯云顾问专区

腾讯云原生专区

腾讯混元专区

腾讯云TCE专区

腾讯云Lighthouse专区

腾讯云HAI专区

腾讯云Edgeone专区

腾讯云存储专区

腾讯云智能专区

腾讯轻联专区 

腾讯云开发专区

TAPD专区

腾讯轻量云游戏服专区

腾讯云最具价值专家

腾讯云架构师技术同盟

腾讯云创作之星

腾讯云开发者先锋

腾讯云代码助手

云原生构建

TAPD 敏捷项目管理

Cloud Studio

SDK中心

API中心

命令行工具

涵盖代码开发、场景应用、自动测试全流程，助你从零构建专属AI助手

一站式MCP教程库，解锁AI应用新玩法

我把这段代码放在一个模型类的构造器中，基于CI的教程，它声明如果你把它放在那里，数据库连接以后可以在那个类中全局使用。由于某些原因，它无法工作，应用程序在代码的该部分崩溃。我的数据库配置很好，因为当我把它放到控制器中时，我可以很好地获取数据库信息。

问$this->load->db()；在类构造函数中初始化？
EN

Stack Overflow用户

社区

活动

圈层

关于

腾讯云开发者

热门产品

热门推荐

更多推荐

问$this->load->db()；在类构造函数中初始化？EN