set_local_infile_handler函数在文件上传处理方面有哪些应用示例？怎么操作？

gitbox 2025-09-12
好的，我明白你的需求。我会按照你的要求用 PHP 编写文章内容，前面和正文之间用水平线分隔，正文讲解 set_local_infile_handler 的应用示例及操作方法。下面是完整文章：
<span><span><span class="hljs-meta">&lt;?php</span></span><span>
</span><span><span class="hljs-comment">// 前置无关代码示例</span></span><span>
</span><span><span class="hljs-keyword">echo</span></span><span> </span><span><span class="hljs-string">"初始化程序环境...\n"</span></span><span>;
</span><span><span class="hljs-variable">$version</span></span><span> = </span><span><span class="hljs-title function_ invoke__">phpversion</span></span><span>();
</span><span><span class="hljs-keyword">echo</span></span><span> </span><span><span class="hljs-string">"当前PHP版本: <span class="hljs-subst">$version</span></span></span><span>\n";
</span><span><span class="hljs-meta">?&gt;</span></span><span>

&lt;hr&gt;

</span><span><span class="hljs-meta">&lt;?php</span></span><span>
<span class="hljs-comment">/*
文章标题：set_local_infile_handler函数在文件上传处理方面有哪些应用示例？怎么操作？
*/</span>

<span class="hljs-comment">/**
 * 1. 什么是 set_local_infile_handler
 * 
 * 在 PHP 中，set_local_infile_handler 是 MySQLi 扩展提供的一个函数，用于自定义处理 MySQL LOAD DATA LOCAL INFILE 上传的文件数据。
 * 它可以让开发者在 MySQL 执行 LOAD DATA LOCAL INFILE 操作时，通过回调函数拦截文件内容并进行处理，而不必依赖本地实际文件。
 *
 * 语法：
 * mysqli::set_local_infile_handler(mysqli $link, callable $handler): bool
 * 
 * 参数：
 * - $link: MySQLi 连接对象
 * - $handler: 回调函数，用于处理文件内容
 *
 * 返回值：
 * - 成功返回 true，失败返回 false
 */</span>

<span class="hljs-comment">/**
 * 2. 上传文件并使用 set_local_infile_handler 示例
 */</span>

</span><span><span class="hljs-variable">$mysqli</span></span><span> = </span><span><span class="hljs-keyword">new</span></span><span> </span><span><span class="hljs-title function_ invoke__">mysqli</span></span><span>(</span><span><span class="hljs-string">"localhost"</span></span><span>, </span><span><span class="hljs-string">"username"</span></span><span>, </span><span><span class="hljs-string">"password"</span></span><span>, </span><span><span class="hljs-string">"test_db"</span></span><span>);

</span><span><span class="hljs-keyword">if</span></span><span> (</span><span><span class="hljs-variable">$mysqli</span></span><span>-&gt;connect_errno) {
    </span><span><span class="hljs-keyword">die</span></span><span>(</span><span><span class="hljs-string">"连接失败: "</span></span><span> . </span><span><span class="hljs-variable">$mysqli</span></span><span>-&gt;connect_error);
}

</span><span><span class="hljs-comment">// 定义文件上传处理回调</span></span><span>
</span><span><span class="hljs-variable">$mysqli</span></span><span>-&gt;</span><span><span class="hljs-title function_ invoke__">set_local_infile_handler</span></span><span>(function(</span><span><span class="hljs-variable">$filename</span></span><span>, </span><span><span class="hljs-variable">$fileHandler</span></span><span>) {
    </span><span><span class="hljs-comment">// 假设 $fileHandler 是一个文件流对象</span></span><span>
    </span><span><span class="hljs-comment">// 这里可以对上传内容进行过滤、转换或其他操作</span></span><span>
    </span><span><span class="hljs-keyword">while</span></span><span> ((</span><span><span class="hljs-variable">$line</span></span><span> = </span><span><span class="hljs-title function_ invoke__">fgets</span></span><span>(</span><span><span class="hljs-variable">$fileHandler</span></span><span>)) !== </span><span><span class="hljs-literal">false</span></span><span>) {
        </span><span><span class="hljs-comment">// 示例：替换逗号为分号</span></span><span>
        </span><span><span class="hljs-variable">$line</span></span><span> = </span><span><span class="hljs-title function_ invoke__">str_replace</span></span><span>(</span><span><span class="hljs-string">","</span></span><span>, </span><span><span class="hljs-string">";"</span></span><span>, </span><span><span class="hljs-variable">$line</span></span><span>);
        </span><span><span class="hljs-keyword">echo</span></span><span> </span><span><span class="hljs-string">"处理数据行: <span class="hljs-subst">$line</span></span></span><span>\n";
    }
});

</span><span><span class="hljs-comment">// 假设客户端上传了 CSV 文件，服务器端执行 LOAD DATA LOCAL INFILE</span></span><span>
</span><span><span class="hljs-variable">$sql</span></span><span> = <span class="hljs-string">&lt;&lt;&lt;SQL
LOAD DATA LOCAL INFILE '上传文件.csv' 
INTO TABLE users 
FIELDS TERMINATED BY ',' 
LINES TERMINATED BY '\n' 
(username, email, age);
SQL</span>;

</span><span><span class="hljs-keyword">if</span></span><span> (</span><span><span class="hljs-variable">$mysqli</span></span><span>-&gt;</span><span><span class="hljs-title function_ invoke__">query</span></span><span>(</span><span><span class="hljs-variable">$sql</span></span><span>)) {
    </span><span><span class="hljs-keyword">echo</span></span><span> </span><span><span class="hljs-string">"数据导入成功！\n"</span></span><span>;
} </span><span><span class="hljs-keyword">else</span></span><span> {
    </span><span><span class="hljs-keyword">echo</span></span><span> </span><span><span class="hljs-string">"导入失败: "</span></span><span> . </span><span><span class="hljs-variable">$mysqli</span></span><span>-&gt;error . </span><span><span class="hljs-string">"\n"</span></span><span>;
}

<span class="hljs-comment">/**
 * 3. 应用场景
 *
 * - 文件数据预处理：在写入数据库之前对数据进行清理、替换或格式化。
 * - 数据安全控制：可以对上传文件进行验证，防止恶意注入。
 * - 避免临时文件存储：无需将文件物理存储在服务器，只通过回调流处理即可。
 */</span>

<span class="hljs-comment">/**
 * 4. 操作步骤总结
 *
 * 1. 使用 MySQLi 连接数据库。
 * 2. 调用 set_local_infile_handler 设置回调函数。
 * 3. 在回调函数中读取和处理文件内容。
 * 4. 使用 LOAD DATA LOCAL INFILE 将数据导入数据库。
 * 5. 根据处理结果返回相应状态。
 */</span>

</span><span><span class="hljs-meta">?&gt;</span></span><span>
</span></span>
set_local_infile_handler