Develop Custom WordPress CRUD Plugin

WordPress is a powerful CMS, but sometimes we need custom solutions for handling data beyond just posts and pages. A CRUD (Create, Read, Update, Delete) operation allows developers to build custom database-driven applications within WordPress. In this guide, we will walk through creating a WordPress CRUD plugin, handling data efficiently, and ensuring a seamless user experience.

What is CRUD?

CRUD stands for:

• Create: Insert new records into a database.

• Read: Retrieve and display existing records.

• Update: Modify existing records.

• Delete: Remove records from the database.

In WordPress, CRUD operations are commonly used for custom post types, user management, and interacting with custom database tables.

Why Use a Custom WordPress CRUD Plugin?

• Better data organisation: Store information in a structured manner.

• Admin panel management: Create an easy-to-use interface for managing data.

• Flexibility: Control how data is stored, retrieved, and displayed.

---

📂 Folder Structure

You'll create the following folder and files inside your WordPress plugins directory:

/wp-content/plugins/wp-crud-plugin/
│── wp-crud-plugin.php            # Main plugin file
│── includes/
│   ├── db.php                    # Database setup
│   ├── admin-page.php             # Admin page UI & logic
│   ├── crud-functions.php         # CRUD operations
│── assets/
│   ├── style.css                  # Styles for the admin UI
│── uninstall.php                  # Cleanup script for deleting data on uninstall

---

📂 Step 1: Create Plugin Folder & Main File

📌 Folder: /wp-content/plugins/wp-crud-plugin/
📌 File: /wp-content/plugins/wp-crud-plugin/wp-crud-plugin.php

📄 Content:

<?php
/**
 * Plugin Name: Custom WP CRUD Plugin
 * Plugin URI:  https://example.com
 * Description: A simple WordPress plugin for CRUD operations.
 * Version:     1.0
 * Author:      Your Name
 * License:     GPL2
 */

if (!defined('ABSPATH')) {
    exit; // Prevent direct access
}

// Define plugin path
define('WP_CRUD_PLUGIN_DIR', plugin_dir_path(__FILE__));

// Include files
require_once WP_CRUD_PLUGIN_DIR . 'includes/db.php';
require_once WP_CRUD_PLUGIN_DIR . 'includes/admin-page.php';
require_once WP_CRUD_PLUGIN_DIR . 'includes/crud-functions.php';

// Activation Hook (Create DB Table)
register_activation_hook(__FILE__, 'wp_crud_create_table');

// Enqueue Styles
function wp_crud_enqueue_assets() {
    wp_enqueue_style('wp-crud-style', plugins_url('assets/style.css', __FILE__));
}
add_action('admin_enqueue_scripts', 'wp_crud_enqueue_assets');

---

📂 Step 2: Create Database Setup File

📌 Folder: /wp-content/plugins/wp-crud-plugin/includes/
📌 File: /wp-content/plugins/wp-crud-plugin/includes/db.php

📄 Content:

<?php
// Database Table Creation
function wp_crud_create_table() {
    global $wpdb;
    $table_name = $wpdb->prefix . 'custom_data';
    $charset_collate = $wpdb->get_charset_collate();

    $sql = "CREATE TABLE $table_name (
        id INT NOT NULL AUTO_INCREMENT,
        name VARCHAR(100) NOT NULL,
        email VARCHAR(100) NOT NULL,
        PRIMARY KEY (id)
    ) $charset_collate;";

    require_once ABSPATH . 'wp-admin/includes/upgrade.php';
    dbDelta($sql);
}

---

📂 Step 3: Create CRUD Operations File

📌 Folder: /wp-content/plugins/wp-crud-plugin/includes/
📌 File: /wp-content/plugins/wp-crud-plugin/includes/crud-functions.php

📄 Content:

<?php
// Insert Record
function wp_crud_insert($name, $email) {
    global $wpdb;
    $table_name = $wpdb->prefix . 'custom_data';
    return $wpdb->insert($table_name, ['name' => sanitize_text_field($name), 'email' => sanitize_email($email)]);
}

// Get All Records
function wp_crud_get_all() {
    global $wpdb;
    $table_name = $wpdb->prefix . 'custom_data';
    return $wpdb->get_results("SELECT * FROM $table_name");
}

// Get Single Record
function wp_crud_get($id) {
    global $wpdb;
    $table_name = $wpdb->prefix . 'custom_data';
    return $wpdb->get_row($wpdb->prepare("SELECT * FROM $table_name WHERE id = %d", $id));
}

// Update Record
function wp_crud_update($id, $name, $email) {
    global $wpdb;
    $table_name = $wpdb->prefix . 'custom_data';
    return $wpdb->update($table_name, ['name' => sanitize_text_field($name), 'email' => sanitize_email($email)], ['id' => $id]);
}

// Delete Record
function wp_crud_delete($id) {
    global $wpdb;
    $table_name = $wpdb->prefix . 'custom_data';
    return $wpdb->delete($table_name, ['id' => $id]);
}

---

📂 Step 4: Create Admin Page

📌 Folder: /wp-content/plugins/wp-crud-plugin/includes/
📌 File: /wp-content/plugins/wp-crud-plugin/includes/admin-page.php

📄 Content:

<?php
// Add Admin Menu
function wp_crud_admin_menu() {
    add_menu_page(
        'Custom CRUD',
        'Custom CRUD',
        'manage_options',
        'wp_crud',
        'wp_crud_render_admin_page',
        'dashicons-database',
        25
    );
}
add_action('admin_menu', 'wp_crud_admin_menu');

function wp_crud_render_admin_page() {
    global $wpdb;
    $table_name = $wpdb->prefix . 'custom_data';

    // Handle Create & Update
    if (isset($_POST['submit'])) {
        if (!empty($_POST['id'])) {
            wp_crud_update($_POST['id'], $_POST['name'], $_POST['email']);
        } else {
            wp_crud_insert($_POST['name'], $_POST['email']);
        }
    }

    // Handle Delete
    if (isset($_GET['delete'])) {
        wp_crud_delete($_GET['delete']);
    }

    // Fetch Data
    $results = wp_crud_get_all();
    $edit_data = isset($_GET['edit']) ? wp_crud_get($_GET['edit']) : null;
    ?>

    <div class="wrap">
        <h1>Custom CRUD Operations</h1>
        <form method="POST">
            <input type="hidden" name="id" value="<?php echo $edit_data ? $edit_data->id : ''; ?>">
            <input type="text" name="name" placeholder="Enter Name" value="<?php echo $edit_data ? esc_attr($edit_data->name) : ''; ?>" required>
            <input type="email" name="email" placeholder="Enter Email" value="<?php echo $edit_data ? esc_attr($edit_data->email) : ''; ?>" required>

            <?php if ($edit_data) : ?>
                <input type="submit" name="submit" value="Update">
                <a href="?page=wp_crud" class="button button-secondary">Cancel Update</a>
            <?php else : ?>
                <input type="submit" name="submit" value="Add Record">
            <?php endif; ?>
        </form>

        <h2>Stored Data</h2>
        <table class="wp-list-table widefat fixed striped">
            <thead>
                <tr>
                    <th>ID</th>
                    <th>Name</th>
                    <th>Email</th>
                    <th>Actions</th>
                </tr>
            </thead>
            <tbody>
                <?php foreach ($results as $row) : ?>
                    <tr>
                        <td><?php echo $row->id; ?></td>
                        <td><?php echo esc_html($row->name); ?></td>
                        <td><?php echo esc_html($row->email); ?></td>
                        <td>
                            <a href="?page=wp_crud&edit=<?php echo $row->id; ?>">Edit</a> |
                            <a href="?page=wp_crud&delete=<?php echo $row->id; ?>" onclick="return confirm('Delete this record?');">Delete</a>
                        </td>
                    </tr>
                <?php endforeach; ?>
            </tbody>
        </table>
    </div>
    <?php
}

---

Step 5: Cleanup on Uninstall

Create uninstall.php inside /wp-content/plugins/wp-crud-plugin/:

📌 Folder: /wp-content/plugins/wp-crud-plugin/
📌 File: /wp-content/plugins/wp-crud-plugin/uninstall.php

📄 Content:

<?php
if (!defined('WP_UNINSTALL_PLUGIN')) {
    exit;
}

global $wpdb;
$table_name = $wpdb->prefix . 'custom_data';
$wpdb->query("DROP TABLE IF EXISTS $table_name");

Conclusion

📂 Step 6: Add CSS for Styling

📌 Folder: /wp-content/plugins/wp-crud-plugin/assets/
📌 File: /wp-content/plugins/wp-crud-plugin/assets/style.css

📄 Content:

input[type="text"], input[type="email"] {
    padding: 5px;
    width: 300px;
    margin-right: 10px;
}
input[type="submit"] {
    padding: 5px 10px;
    background: #0073aa;
    color: white;
    border: none;
    cursor: pointer;
}

---

✅ Final Steps

1. Upload the wp-crud-plugin folder to /wp-content/plugins/.

2. Go to WordPress Admin > Plugins > Activate "Custom WP CRUD Plugin".

3. Access "Custom CRUD" from the sidebar.

🎉 Your WordPress CRUD plugin is now fully functional! 🚀