在非WordPress文件中的函数中调用$ wpdb

Playing around with the query SHOW TABLE STATUS in a non-WordPress core/plugin/template file using wp-load.php to access WordPress functions and database connection.

require_once('wp-load.php');

function mysqlInfo() {
    $info = $wpdb->get_results('SHOW TABLE STATUS');
    foreach($info as $table) {
        echo $table->name;
    }
}

I keep running into this error:

Fatal error: Call to a member function get_results() on a non-object in /../../../file.php

I have tried declaring $wpdb as a global variable and tried creating a new class out of $wpdb

You have to declare the global variable within the function

function mysqlInfo() {
global $wpdb;
$info = $wpdb->get_results('SHOW TABLE STATUS');
foreach($info as $table) {
    echo $table->Name;
}}