如何在Wordpress插件中包含$ wpdb? [英] How to include $wpdb in wordpress plugin?

问题描述

我已经在wordpress中的plugin上开发了一段时间，但是一个问题一直困扰着我.我想将数据库表导出为ex​​cel文件，因此我需要从插件目录中的文件访问全局$wpdb->variable.

I've been developing for some time on a plugin in wordpress, but one problem keeps bugging me. I want to export a database-table as an excel file and therefor i need access to the global $wpdb->variable from a file in my plugin directory.

我找到了一个博客条目，该条目解释了我应该包括哪些类，但这是行不通的(下面是链接).如您所见，我执行var_dump，但从未达到该点.如果我在代码中未包含wp-config和wp-load的包含内容，则转储returns NULL，所以我猜测导入存在问题.

I found a blog entry that explains what classes i should include, but this doesn't work (link is below). As you can see, i do a var_dump, but it never reaches that point. If i leave the includes of wp-config and wp-load out of the code, the dump returns NULL, so i'm guessing there is a problem with the imports.

无论如何，我希望有人可以帮助我解决这个问题.我的方法不一定需要修复，我只需要一种方法(可以从我的数据库中获取)导出数据数组以在WordPress中表现出色.任何帮助，将不胜感激.预先感谢.

Anyway, i was hoping someone could help me with this problem. I don't necessarily need a fix for my approach, I just need a way to export an array of data (fetched from my db) to excel in wordpress. Any help would be appreciated. Thanks in advance.

http://www.notesbit.com/index.php/web-mysql/web-scripts/standalone-access-the-wordpress-database-using-wpdb/

include_once('../../../wp-config.php');
include_once('../../../wp-load.php');
include_once('../../../wp-includes/wp-db.php');

var_dump($wpdb);
$filter = get_where_clause();
$order = get_order_by_clause();

$data = $wpdb->get_results("SELECT * FROM " . $table_prefix . "team_data" . $filter . $order, ARRAY_A);

$result = array();

---

我不能包含wp-config，它会给出恒定的错误.我知道错误发生在哪里，我只需要找到一种解决方法.当查看wp-settings页面(wp-config包含)时，您会发现以下代码行:

---

I cannot include the wp-config, it gives constant errors. I know where the bug is taking place, I just need to find a work-around. when looking at the wp-settings page (which is included by the wp-config) you will find this line of code:

foreach ( wp_get_active_and_valid_plugins() as $plugin )
    include_once( $plugin );
unset( $plugin );

这是一个存在错误的地方.我只是不知道我应该如何解决这个错误.

this is where there is a bug. I just don't know how i should work around this bug.

问题解决了.当包含文件时，我多次包含了wp-config(即使我声明只应包含一次).我通过使用以下代码解决了这个问题.

EDIT 2: Problem solved. When including the file, i included the wp-config more than once (even though i stated it should only be included one time). I solved the problem by using the following code.

global $wpdb, $table_prefix;

if(!isset($wpdb))
{
    require_once('../../../../wp-config.php');
    require_once('../../../../wp-includes/wp-db.php');
}

推荐答案

如果要创建WordPress插件，则无需手动添加这些文件.

If you're creating a WordPress plugin, you don't need to include those files manually.

如果要导出表，为什么不为它创建一个函数/类并将$wpdb传递给它(如果需要).您还可以使用普通的 MySQLi 类(来自PHP)来访问您的MySQL数据库.

If you want to export your table, why don't you create a function/class for it and pass the $wpdb to it (if you need it). You can also use the normal MySQLi-class (from PHP) do access your MySQL Database.

如果您只想使用WordPress使用的已存储登录值访问MySQL数据库，则可以在WordPress根目录中包含wp_config文件.它具有一些(自解释)全局字段，可用于连接数据库:

If you simply want to access the MySQL Database with the stored login-values which are used by WordPress, you can include the wp_config-file from the WordPress root-directory. It has some (self explaining) global fields which you could use to connect to your database:

include "WP-ROOT-PATH/wp-config.php";
$db = new mysqli(DB_HOST, DB_USER, DB_PASSWORD, DB_NAME);
// Test the connection:
if (mysqli_connect_errno()){
    // Connection Error
    exit("Couldn't connect to the database: ".mysqli_connect_error());
}

之后，您将拥有一个MySQLi类的实例(如上所述)，可用于访问数据库.

After that you have a instance of the MySQLi-class (as mentioned above) which you can use to access your Database.

但是我不确定这是否是理想的选择，但是它确实有效.

I'm however not sure if this is the perfect way to go but it sure works.

要调试WordPress(如果某些操作不起作用并且没有错误消息)，应在wp-config.php文件中激活调试:

To Debug WordPress (if something doesn't work and there is no Error-Message) you should activate debugging in the wp-config.php-file:

/**
 * For developers: WordPress debugging mode.
 *
 * Change this to true to enable the display of notices during development.
 * It is strongly recommended that plugin and theme developers use WP_DEBUG
 * in their development environments.
 */
define('WP_DEBUG', true);

此外，如果要在本地服务器上测试PHP脚本，则应在php.ini文件中将display_error转换为on:

Also, if you're testing your PHP-Scripts on a local server, you should turn the display_error to on in your php.ini-file:

; This directive controls whether or not and where PHP will output errors,
; notices and warnings too. Error output is very useful during development, but
; it could be very dangerous in production environments.
display_errors = On

但是，仅应在本地测试服务器上执行此操作，而不是在生产环境中进行此操作.

However this should only be done on your local test-server, not in a productive scenario.

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