PHP代码示例：商城SKU库存管理系统的实现方法

class SKU {
    private $sku_code;
    private $product_id;
    private $attribute_id;

    public function __construct($sku_code, $product_id, $attribute_id) {
        $this->sku_code = $sku_code;
        $this->product_id = $product_id;
        $this->attribute_id = $attribute_id;
    }

    // Getter methods
    public function getSKUCode() {
        return $this->sku_code;
    }

    public function getProductID() {
        return $this->product_id;
    }

    public function getAttributeID() {
        return $this->attribute_id;
    }
}

class InventoryManager {
    private $sku_inventory;

    public function __construct() {
        $this->sku_inventory = array();
    }

    // Add sku to inventory
    public function addSKU(SKU $sku) {
        array_push($this->sku_inventory, $sku);
    }

    // Update sku inventory
    public function updateSKUInventory($sku_code, $inventory) {
        foreach ($this->sku_inventory as $sku) {
            if ($sku->getSKUCode() == $sku_code) {
                // Update inventory
                // ...
                break;
            }
        }
    }

    // Get sku inventory
    public function getSKUInventory($sku_code) {
        foreach ($this->sku_inventory as $sku) {
            if ($sku->getSKUCode() == $sku_code) {
                // Return inventory
                // ...
                break;
            }
        }
    }
}

$inventory_manager = new InventoryManager();

// Add SKU to inventory
$sku = new SKU("SKU001", 1, 1);
$inventory_manager->addSKU($sku);

// Update SKU inventory
$inventory_manager->updateSKUInventory("SKU001", 10);