Tables: `smartphones`, `specs`, `inventory`, `orders`, `price_alerts`, `brands`, `users` with indexes for filtering & sorting.

-- 76mobiles MySQL Schema for phpMyAdmin
CREATE DATABASE IF NOT EXISTS `76mobiles` DEFAULT CHARACTER SET utf8mb4;
USE `76mobiles`;

CREATE TABLE `smartphones` (
  `id` VARCHAR(64) PRIMARY KEY,
  `name` VARCHAR(128) NOT NULL,
  `brand` VARCHAR(64) NOT NULL,
  `tagline` VARCHAR(255),
  `base_price` DECIMAL(10,2) NOT NULL,
  `score_91` INT NOT NULL DEFAULT 85,
  `rating` DECIMAL(2,1) DEFAULT 4.5,
  `reviews_count` INT DEFAULT 1000,
  `created_at` TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
  INDEX `idx_brand_price` (`brand`, `base_price`),
  INDEX `idx_score` (`score_91`)
) ENGINE=InnoDB;

CREATE TABLE `specs` (
  `phone_id` VARCHAR(64) PRIMARY KEY,
  `chipset` VARCHAR(128) NOT NULL,
  `ram` VARCHAR(32) NOT NULL,
  `storage` VARCHAR(32) NOT NULL,
  `display_size` VARCHAR(32),
  `panel_type` VARCHAR(32),
  `primary_camera` VARCHAR(64),
  `front_camera` VARCHAR(64),
  `battery` VARCHAR(64),
  `network` VARCHAR(16) DEFAULT '5G',
  FOREIGN KEY (`phone_id`) REFERENCES `smartphones`(`id`) ON DELETE CASCADE
) ENGINE=InnoDB;

CREATE TABLE `orders` (
  `id` VARCHAR(64) PRIMARY KEY,
  `order_number` VARCHAR(32) UNIQUE,
  `customer_name` VARCHAR(128) NOT NULL,
  `customer_email` VARCHAR(128) NOT NULL,
  `device_id` VARCHAR(64) NOT NULL,
  `amount` DECIMAL(10,2) NOT NULL,
  `status` ENUM('Pending', 'Confirmed', 'Shipped', 'Delivered') DEFAULT 'Pending',
  `created_at` TIMESTAMP DEFAULT CURRENT_TIMESTAMP
) ENGINE=InnoDB;
                    

Pure PDO controller handling AJAX GET queries with dynamic filters (brand, budget, 5G, ram, sort).

<?php
namespace App\Controllers;

class SmartphoneController {
  public function getSmartphones() {
    header('Content-Type: application/json');
    $db = \App\Core\Database::getInstance()->getConnection();
    
    $where = ["1=1"];
    $params = [];
    
    if (!empty($_GET['brand'])) {
      $where[] = "s.brand = :brand";
      $params[':brand'] = $_GET['brand'];
    }
    if (!empty($_GET['max_price'])) {
      $where[] = "s.base_price <= :max_price";
      $params[':max_price'] = (float)$_GET['max_price'];
    }
    
    $sql = "SELECT s.*, sp.chipset, sp.ram, sp.battery, sp.primary_camera 
            FROM smartphones s 
            LEFT JOIN specs sp ON s.id = sp.phone_id 
            WHERE " . implode(" AND ", $where) . " 
            ORDER BY s.score_91 DESC";
            
    $stmt = $db->prepare($sql);
    $stmt->execute($params);
    $data = $stmt->fetchAll(\PDO::FETCH_ASSOC);
    
    echo json_encode(['status' => 'success', 'data' => $data]);
    exit;
  }
}