PHP连接MySQL-踩坑总结

r囧r小猫 2022-12-22 11:12 173阅读 0赞

### 文章目录 ###

*  写在前面
 *  mysqli扩展
 *  MySQL权限
 *  测试

# 写在前面 #

--------------------

版本迭代，网上很多解决方法都失效了，在此记录一下。  
版本：PHP7.4+MySQL8.0

PHP安装可参考：[PHP安装配置(Windows和Linux)-一篇就够了][PHP_Windows_Linux_-]  
Apache安装可参考：[Apache安装配置(Windows和Linux)-有手就行][Apache_Windows_Linux_-]  
![在这里插入图片描述][20201119220150704.png_pic_center]

# mysqli扩展 #

--------------------

> Fatal error: Uncaught Error: Call to undefined function mysqli\_connect() in D:\\tools\\Apache24\\htdocs\\UIUE\\index.php:6 Stack trace: \#0 \{main\} thrown in

PHP7之后就移除了mysql扩展（可以自己打补丁 ），而是推荐使用mysqli扩展和pdo\_mysql。

启用mysqli扩展：

1.  在PHP安装目录下以记事本方式打开pgp.ini  
    ![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzQ1MDM0NzA4_size_16_color_FFFFFF_t_70_pic_center]
2.  搜索`extension=mysqli`，去掉前面`;`  
    ![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzQ1MDM0NzA4_size_16_color_FFFFFF_t_70_pic_center 1]
3.  搜索`extension_dir`，修改/ext所在位置  
    ![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzQ1MDM0NzA4_size_16_color_FFFFFF_t_70_pic_center 2]  
    然后建议重启下Apache
4.  测试

<?php
    	phpinfo();
    ?>

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzQ1MDM0NzA4_size_16_color_FFFFFF_t_70_pic_center 3]

> （插播反爬信息 ）博主CSDN地址：[https://wzlodq.blog.csdn.net/][https_wzlodq.blog.csdn.net]

# MySQL权限 #

--------------------

> Warning: mysqli\_connect(): (HY000/1045): Access denied for user ‘root’@‘localhost’ (using password: YES) in D:\\tools\\Apache24\\htdocs\\UIUE\\index.php on line 6  
> Error: Unable to connect to MySQL. Debugging errno: 1045 Debugging error: Access denied for user ‘root’@‘localhost’ (using password: YES)

1.  修改root密码

use mysql;
    ALTER USER 'root'@'localhost' IDENTIFIED WITH MYSQL_NATIVE_PASSWORD BY '新密码';

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzQ1MDM0NzA4_size_16_color_FFFFFF_t_70_pic_center 4]

1.  授权

grant all privileges on *.* to root@localhost;
    flush privileges;

![在这里插入图片描述][20201119231445598.png_pic_center]

# 测试 #

--------------------

<?php
    $servername = "localhost";
    $username = "root";
    $password = "password";//改成你的密码
    
    $link = mysqli_connect($servername, $username, $password);
    
    if (!$link) { 
        echo "Error: Unable to connect to MySQL." . PHP_EOL;
        echo "Debugging errno: " . mysqli_connect_errno() . PHP_EOL;
        echo "Debugging error: " . mysqli_connect_error() . PHP_EOL;
        exit;
    }
    
    echo "Success: A proper connection to MySQL was made! The my_db database is great.\n" . PHP_EOL;
    echo "Host information: " . mysqli_get_host_info($link) . PHP_EOL;
    
    mysqli_close($link);
    ?>

![在这里插入图片描述][20201119232330770.png_pic_center]  
至此PHP就成功连接MySQL了o(\*￣▽￣\*)o，mysqli相关用法可查[官方文档][Link 1]。  
![在这里插入图片描述][20201119233439602.gif_pic_center]

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[PHP_Windows_Linux_-]: https://wzlodq.blog.csdn.net/article/details/108542598
[Apache_Windows_Linux_-]: https://wzlodq.blog.csdn.net/article/details/108565486
[20201119220150704.png_pic_center]: /images/20221120/74d3b00cc46142a48bf6b3fb7d2e60fc.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzQ1MDM0NzA4_size_16_color_FFFFFF_t_70_pic_center]: /images/20221120/b121a007b74d4c3eae52fae4bd819b15.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzQ1MDM0NzA4_size_16_color_FFFFFF_t_70_pic_center 1]: /images/20221120/a83817ece16d4dcca846dd6ac6b53223.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzQ1MDM0NzA4_size_16_color_FFFFFF_t_70_pic_center 2]: /images/20221120/4681f624e6974aa2a6aa2e5c2ce56a49.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzQ1MDM0NzA4_size_16_color_FFFFFF_t_70_pic_center 3]: /images/20221120/addf762b5fc74ed5ab68492b11d0e19e.png
[https_wzlodq.blog.csdn.net]: https://wzlodq.blog.csdn.net/
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzQ1MDM0NzA4_size_16_color_FFFFFF_t_70_pic_center 4]: /images/20221120/b1f92efcb6704a9b8875be23599a25fc.png
[20201119231445598.png_pic_center]: /images/20221120/9842e0db9fe44f859ff299ec02357032.png
[20201119232330770.png_pic_center]: /images/20221120/55df9e0914934f589183107ccab0f1d2.png
[Link 1]: https://www.php.net/manual/en/mysqli.prepare.php
[20201119233439602.gif_pic_center]: /images/20221120/1f0e458ac6914e109f1cf50185b0d1ca.png