External DB Dummy Plugin for WordPress

This repo demonstrates how to connect a WordPress plugin to one or more external databases, using basic hardcoded connection pooling logic (no GUI, no config screen).

🧠 Idea

• WordPress core continues to use its main database (DB1)
• This plugin connects to an external database (DB2) with custom logic
• Heavy plugin data (e.g. products, prices, logs, etc.) can be stored outside of the main WP database
• Helps reduce bloat and performance load on the main WordPress database

💡 Example Use Case

Imagine you're building a large plugin like a shop, a CRM, or a directory.
Instead of dumping thousands of rows into wp_postmeta, your plugin uses a separate database.

This project shows how to do that with a minimal setup.

📦 Idea Example

Under the folder the-idea/ you will find this hardcoded example:

External-DB-Dummy-Plugin-for-WordPress/
└── the-idea/
    ├── plugin-core.php      ← Simple example plugin file
    ├── db-config.php        ← Hardcoded DB hosts + weights
    └── external-db.php      ← Connection pooling logic

🔧 db-config.php

<?php
// Hardcoded database pool (can be extended later)
return [
    'mydb1' => ['host' => '127.0.0.1', 'user' => 'user1', 'pass' => 'pw1', 'db' => 'plugin_db_1', 'weight' => 2],
    'mydb2' => ['host' => '127.0.0.2', 'user' => 'user2', 'pass' => 'pw2', 'db' => 'plugin_db_2', 'weight' => 1],
];

🔌 external-db.php

<?php

function get_external_db_connection() {
    $configs = require __DIR__ . '/db-config.php';

    // Basic weight-based connection selection (manual pool)
    $pool = [];
    foreach ($configs as $key => $cfg) {
        for ($i = 0; $i < $cfg['weight']; $i++) {
            $pool[] = $cfg;
        }
    }

    $selected = $pool[array_rand($pool)];

    $mysqli = new mysqli($selected['host'], $selected['user'], $selected['pass'], $selected['db']);

    if ($mysqli->connect_error) {
        error_log("External DB connection failed: " . $mysqli->connect_error);
        return null;
    }

    return $mysqli;
}

🔌 plugin-core.php

<?php
/**
 * Plugin Name: External DB Dummy Plugin
 * Description: A simple plugin that connects to an external DB with manual connection pooling (no GUI).
 * Version: 0.1
 * Author: Als Batman :D
 */

require_once __DIR__ . '/external-db.php';

add_action('admin_notices', function () {
    $conn = get_external_db_connection();
    if (!$conn) {
        echo "<div class='notice notice-error'><p>External DB connection failed.</p></div>";
        return;
    }

    $result = $conn->query("SELECT * FROM products LIMIT 5");
    echo "<div class='notice notice-success'><p>External DB connected. Found " . $result->num_rows . " products.</p></div>";
});

📁 Examples

In the /examples/ folder you can find a simple directory plugin that uses a second database.

📌 Notes

• This plugin does not use $wpdb
• No options or settings in WordPress
• Pure PHP + mysqli
• Connection pooling is simulated with a weighted array

🔐 Requirements

• PHP 7.4+
• mysqli extension enabled
• WordPress 5.0+
• External databases accessible from the WordPress host

Created by thought. Readme written by OpenAI's GPT. Heartbeat and code by a human soul.

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Made by VolkanSah :D – Giving WordPress plugins their own brains. "Between madness and genius lies a README.md."